dk

3. Building Construction Illustrated

5. Building Construction
Illustrated
Fifth Edition
Francis D.K. Ching

6. LibraryofCongressCataloging-in-PublicationData:
Ching,Frank,1943-
Buildingconstructionillustrated/FrancisD.K.Ching.--Fifthedition.
pagescm
Includesindex.
ISBN978-1-118-45834-1(pbk.)
1. Building.2. Houseconstruction. I.Title.
TH146.C522014
690--dc23
2013016213
PrintedintheUnitedStatesofAmerica
10 9 8 7 6 5 4 3 2 1
CoverDesign:Wiley
CoverImage:courtesyofFrancisD.K.Ching
Thisbookisprintedonacid-freepaper. ∞
Copyright©2014byJohnWiley&Sons.Allrightsreserved
PublishedbyJohnWiley&Sons,Inc.,Hoboken,NewJersey
PublishedsimultaneouslyinCanada
Nopartofthispublicationmaybereproduced,storedinaretrievalsystem,ortransmittedinanyformorby
anymeans,electronic,mechanical,photocopying,recording,scanning,orotherwise,exceptaspermittedunder
Section107or108ofthe1976UnitedStatesCopyrightAct,withouteitherthepriorwrittenpermission
ofthePublisher,orauthorizationthroughpaymentoftheappropriateper-copyfeetotheCopyrightClearance
Center,222RosewoodDrive,Danvers,MA01923,(978)750-8400,fax(978)646-8600,orontheweb
atwww.copyright.com.RequeststothePublisherforpermissionshouldbeaddressedtothePermissions
Department,JohnWiley&Sons,Inc.,111RiverStreet,Hoboken,NJ07030,(201)748-6011,fax(201)
748-6008,oronlineatwww.wiley.com/go/permissions.
LimitofLiability/DisclaimerofWarranty:Whilethepublisherandauthorhaveusedtheirbestefforts
inpreparingthisbook,theymakenorepresentationsorwarrantieswiththerespecttotheaccuracyor
completenessofthecontentsofthisbookandspecificallydisclaimanyimpliedwarrantiesofmerchantability
orfitnessforaparticularpurpose.Nowarrantymaybecreatedorextendedbysalesrepresentativesorwritten
salesmaterials. Theadviceandstrategiescontainedhereinmaynotbesuitableforyoursituation.Youshould
consultwithaprofessionalwhereappropriate.Neitherthepublishernortheauthorshallbeliablefordamages
arisingherefrom.
Forgeneralinformationaboutourotherproductsandservices,pleasecontactourCustomerCareDepartment
withintheUnitedStatesat(800)762-2974,outsidetheUnitedStatesat(317)572-3993orfax(317)
572-4002.
Wileypublishesinavarietyofprintandelectronicformatsandbyprint-on-demand.Somematerialincluded
withstandardprintversionsofthisbookmaynotbeincludedine-booksorinprint-on-demand.Ifthisbook
referstomediasuchasaCDorDVDthatisnotincludedintheversionyoupurchased,youmaydownloadthis
materialathttp://booksupport.wiley.com.FormoreinformationaboutWileyproducts,visitwww.wiley.com.

7. CONTENTS
Preface
1 • THE BUILDING SITE
2 • THE BUILDING
3 • FOUNDATION SYSTEMS
4 • FLOOR SYSTEMS
5 • WALL SYSTEMS
6 • ROOF SYSTEMS
7 • MOISTURE & THERMAL PROTECTION
8 • DOORS & WINDOWS
9 • SPECIAL CONSTRUCTION
10 • FINISH WORK
11 • MECHANICAL & ELECTRICAL SYSTEMS
12 • NOTES ON MATERIALS
A • APPENDIX
Bibliography
Index

9. Thefirsteditionofthisillustratedguidetobuildingconstructionappearedin1975,introducingstudentsandbuilders
ofarchitecturetothefundamentalprinciplesthatgovernhowbuildingsareerected.Itmarkedtheemergenceofavisual
approachtounderstandingtherelationshipbetweendesignandconstruction.
In1991,thesecondeditionprovidedamoreexpansivesurveyofbuildingconstructionbyaddingcoverageofstructural
steel,reinforcedconcrete,andcurtainwallsystems.Thethirdeditionin2001remainedacomprehensiveintroductionto
theprinciplesunderlyingbuildingconstructionwhilerefiningthegraphicformatandorganizationofthefirsttwoeditions,
incorporatinganexpandeddiscussionofstructuralprinciples,elements,andsystemsandreferencingtheAmericanswith
DisabilitiesActAccessibilityGuidelinesandtheMasterFormat™systemestablishedbytheConstructionsSpecifications
Institute(CSI)fororganizingconstructioninformation.
Thefourtheditionin2008introducedtheLEED®GreenBuildingRatingSystem™inChapterOneandreferenced
specificLEEDcriteriawhereverappropriate;updatedsectionnumberstocorrespondtothe2004editionoftheCSI
MasterFormat™system;andcompliedwiththerequirementsofthe2006editionoftheInternationalBuildingCode®.
Acommonthreadthatwoveitselfthroughthefirstfoureditionsandcontinuesinthisfiftheditionistheattitudethat
buildingsandsitesshouldbeplannedanddevelopedinanenvironmentallysensitivemanner,respondingtocontextand
climatetoreducetheirrelianceonactiveenvironmentalcontrolsystemsandtheenergytheyconsume.Thisedition
thereforecontinuestoreferencethelatesteditionoftheLEED®GreenBuildingRatingSystem™criteriaandthesection
numbersofthe2012CSIMasterFormat™systemwhereverappropriate.Manyofthechangesandadditionsinthisfifth
edition,suchasupdatinginformationinlightingtechnologiesandwaysinwhichtoreduceenergyusageinbuildings,are
incrementalandoftensubtle,buttogethertheycompriseacontinuingcommitmenttobuildwiselyandsustainably.
Itwouldbenearlyimpossibletocoverallbuildingmaterialsandconstructiontechniques,buttheinformationpresented
hereinshouldbeapplicabletomostresidentialandcommercialconstructionsituationsencounteredtoday.Construction
techniquescontinuetoadjusttothedevelopmentofnewbuildingmaterials,products,andstandards.Whatdoesnot
changearethefundamentalprinciplesthatunderliebuildingelementsandthewaysinwhichsystemsareconstructed.
Thisillustratedguidefocusesontheseprinciples,whichcanserveasguidepostswhenevaluatingandapplyingnew
informationencounteredintheplanning,design,andconstructionofabuilding.
Eachbuildingelement,component,orsystemisdescribedintermsofitsenduse.Thespecificform,quality,capability,
andavailabilityofanelementorcomponentwillvarywithmanufacturerandlocale.Itisthereforeimportanttoalways
followthemanufacturer’srecommendationintheuseofamaterialorproductandtopaycarefulattentiontothebuilding
coderequirementsineffectfortheuseandlocationofaplannedbuilding.Itistheuser’sresponsibilitytoascertainthe
appropriatenessoftheinformationcontainedinthishandbookandtojudgeitsfitnessforanyparticularpurpose.Seek
theexpertadviceofaprofessionalwhenneeded.
Metric Equivalents
TheInternationalSystemofUnitsisaninternationallyacceptedsystemofcoherentphysicalunits,usingthemeter,
kilogram,second,ampere,kelvin,andcandelaasthebaseunitsoflength,mass,time,electriccurrent,temperature,
andluminousintensity.ToacquaintthereaderwiththeInternationalSystemofUnits,metricequivalentsareprovided
throughoutthisbookaccordingtothefollowingconventions:
• Allwholenumbersinparenthesesindicatemillimetersunlessotherwisenoted.
• Dimensions3inchesandgreaterareroundedtothenearestmultipleof5millimeters.
• Nominaldimensionsaredirectlyconverted;forexample,anominal2x4isconvertedto51x100
eventhoughitsactual1-1/2"x3-1/2"dimensionswouldbeconvertedto38x90.
• Notethat3487mm=3.487m.
• Inallothercases,themetricunitofmeasurementisspecified.
• RefertotheAppendixformetricconversionfactors.
PREFACE

11. THE BUILDING SITE
1
1.02 Building in Context
1.03 Sustainability
1.04 Green Building
1.05 LEED® Green Building Rating System
1.06 The 2030 Challenge
1.07 Site Analysis
1.08 Soils
1.09 Soil Mechanics
1.10 Topography
1.12 Plant Materials
1.13 Trees
1.14 Solar Radiation
1.16 Passive Solar Design
1.18 Solar Shading
1.19 Daylighting
1.20 Precipitation
1.21 Site Drainage
1.22 Wind
1.23 Sound & Views
1.24 Regulatory Factors
1.25 Zoning Ordinances
1.26 Site Access & Circulation
1.27 Pedestrian Circulation
1.28 Vehicular Circulation
1.29 Vehicular Parking
1.30 Slope Protection
1.31 Retaining Walls
1.34 Paving
1.36 The Site Plan
1.38 Site Description

12. 1.02 BUILDING IN CONTEXT
Buildingsdonotexistinisolation.Theyareconceivedtohouse,
support,andinspirearangeofhumanactivitiesinresponseto
sociocultural,economic,andpoliticalneeds,andareerectedin
naturalandbuiltenvironmentsthatconstrainaswellasoffer
opportunitiesfordevelopment.Weshouldthereforecarefully
considerthecontextualforcesthatasitepresentsinplanningthe
designandconstructionofbuildings.
Themicroclimate,topography,andnaturalhabitatofasiteall
influencedesigndecisionsataveryearlystageinthedesign
process.Toenhancehumancomfortaswellasconserveenergyand
materialresources,responsiveandsustainabledesignrespects
theindigenousqualitiesofaplace,adaptstheformandlayoutof
abuildingtothelandscape,andtakesintoaccountthepathofthe
sun,therushofthewind,andtheflowofwateronasite.
Inadditiontoenvironmentalforces,thereexisttheregulatory
forcesofzoningordinances.Theseregulationstakeintoaccount
existingland-usepatternsandprescribetheacceptableusesand
activitiesforasiteaswellaslimitthesizeandshapeofthebuilding
massandwhereitmaybelocatedonthesite.
Justasenvironmentalandregulatoryfactorsinfluencewhereand
howdevelopmentoccurs,theconstruction,use,andmaintenance
ofbuildingsinevitablyplaceademandontransportationsystems,
utilities,andotherservices.Afundamentalquestionwefaceis
howmuchdevelopmentasitecansustainwithoutexceedingthe
capacityoftheseservicesystems,consumingtoomuchenergy,or
causingenvironmentaldamage.
Considerationofthesecontextualforcesonsiteandbuildingdesign
cannotproceedwithoutabriefdiscussionofsustainability.

13. SUSTAINABILITY 1.03
In1987,theUnitedNationsWorldCommissiononEnvironment
andDevelopment,chairedbyGroHarlemBrundtland,formerPrime
MinisterofNorway,issuedareport,Our Common Future.Among
itsfindings,thereportdefinedsustainabledevelopmentas“a
formofdevelopmentthatmeetstheneedsofthepresentwithout
compromisingtheabilityoffuturegenerationstomeettheirown
needs.”
Increasingawarenessoftheenvironmentalchallengespresentedby
climatechangeandresourcedepletionhaspushedsustainability
intobecomingasignificantissueshapinghowthebuildingdesign
industryoperates.Sustainabilityisnecessarilybroadinscope,
affectinghowwemanageresourcesaswellasbuildcommunities,
andtheissuecallsforaholisticapproachthatconsidersthesocial,
economic,andenvironmentalimpactsofdevelopmentandrequires
thefullparticipationofplanners,architects,developers,building
owners,contractors,manufacturers,aswellasgovernmentaland
non-governmentalagencies.
Inseekingtominimizethenegativeenvironmentalimpactof
development,sustainabilityemphasizesefficiencyandmoderation
intheuseofmaterials,energy,andspatialresources.Buildingina
sustainablemannerrequirespayingattentiontothepredictable
andcomprehensiveoutcomesofdecisions,actions,andevents
throughoutthelifecycleofabuilding,fromconceptiontothesiting,
design,construction,use,andmaintenanceofnewbuildingsaswell
astherenovationprocessforexistingbuildingsandthe
reshapingofcommunitiesandcities.
Phase
• Planning
• Development
• Design
• Construction
• Use&Operation
• Maintenance
• Modification
• Deconstruction
Resources
• Land
• Materials
• Water
• Energy
• Ecosystems
Principles
• Reduceresourceconsumption
• Reuseresources
• Recycleresourcesforreuse
• Protectnature
• Eliminatetoxics
• Applylife-cyclecosting
• Focusonquality
Framework for Sustainable Development
In1994TaskGroup16oftheInternationalCouncilforResearch
andInnovationinBuildingandConstructionproposedathree-
dimensionalframeworkforsustainabledevelopment.

14. 1.04 GREEN BUILDING
Theterms“greenbuilding”and“sustainabledesign”areoften
usedinterchangeablytodescribeanybuildingdesignedinan
environmentallysensitivemanner.However,sustainabilitycallsfor
awhole-systemsapproachtodevelopmentthatencompassesthe
notionofgreenbuildingbutalsoaddressesbroadersocial,ethical,
andeconomicissues,aswellasthecommunitycontextofbuildings.
Asanessentialcomponentofsustainability,greenbuildingseeksto
providehealthyenvironmentsinaresource-efficientmannerusing
ecologicallybasedprinciples.
Greenbuildingisincreasinglygovernedbystandards,suchasthe
LeadershipinEnergyandEnvironmentalDesign(LEED®)Green
BuildingRatingSystem™,whichprovidesasetofmeasurable
criteriathatpromoteenvironmentallysustainableconstruction.
TheratingsystemwasdevelopedbytheU.S.GreenBuildingCouncil
(USGBC)asaconsensusamongitsmembers—federal/state/local
agencies,suppliers,architects,engineers,contractors,andbuilding
owners—andiscontinuallybeingevaluatedandrefinedinresponse
tonewinformationandfeedback.InJuly2003Canadaobtained
alicensefromtheUSGBCtoadapttheLEEDratingsystemto
Canadiancircumstances.
TheLEEDratingsystemfornewconstructionaddressesseven
majorareasofdevelopment.
1. Sustainable Sites
dealswithreducingthepollutionassociatedwithconstruction
activity,selectingsitesappropriatefordevelopment,protecting
environmentallysensitiveareasandrestoringdamagedhabitats,
encouragingalternativemodesoftransportationtoreduce
theimpactofautomobileuse,respectingthenaturalwater
hydrologyofasite,andreducingtheeffectsofheatislands.
2. Water Efficiency
promotesreducingthedemandforpotablewaterandthe
generationofwastewaterbyusingwater-conservingfixtures,
capturingrainwaterorrecycledgraywaterforconveyingsewage,
andtreatingwastewaterwithon-sitesystems.
LEED®
Toaiddesigners,builders,andownersachieveLEED
certificationforspecificbuildingtypesandphaseofa
buildinglifecycle,theUSGBChasdevelopedanumberof
versionsoftheLEEDratingsystem:
• LEEDforNewConstructionandMajorRenovations
• LEEDforExistingBuildings:Operations&Maintenance
• LEEDforCommercialInteriors
• LEEDforCore&Shell
• LEEDforSchools
• LEEDforRetail
• LEEDforHealthcare
• LEEDforHomes
• LEEDforNeighborhoodDevelopment

15. LEED® GREEN BUILDING RATING SYSTEM 1.05
5. Indoor Environmental Quality
promotestheenhancedcomfort,productivity,andwell-beingof
buildingoccupantsbyimprovingindoorairquality,maximizing
daylightingofinteriorspaces,enablingusercontrolof
lightingandthermalcomfortsystemstosuittaskneedsand
preferences,andminimizingtheexposureofbuildingoccupants
topotentiallyhazardousparticulatesandchemicalpollutants,
suchasthevolatileorganiccompounds(VOC)containedin
adhesivesandcoatingsandtheurea-formaldehyderesinsin
compositewoodproducts.
6. Innovation in Design
rewardsexceedingtherequirementssetbytheLEEDGreen
BuildingRatingSystemand/ordemonstratinginnovative
performanceinGreenBuildingcategoriesnotspecifically
addressedbytheLEEDGreenBuildingRatingSystem.
7. Regional Priority
providesincentivesforpracticesthataddressgeographically-
specificenvironmentalpriorities.
3. Energy and Atmosphere
encouragesincreasingtheefficiencywithwhichbuildings
andtheirsitesacquireanduseenergy,increasingrenewable,
nonpollutingenergysourcestoreducetheenvironmentaland
economicimpactsassociatedwithfossilfuelenergyuse,and
minimizingtheemissionsthatcontributetoozonedepletionand
globalwarming.
4. Materials and Resources
seekstomaximizetheuseoflocallyavailable,rapidlyrenewable
andrecycledmaterials,reducewasteandthedemandfor
virginmaterials,retainculturalresources,andminimizethe
environmentalimpactsofnewbuildings.

16. 1.06 THE 2030 CHALLENGE
Architecture2030isanenvironmentaladvocacygroupwhose
missionis“toprovideinformationandinnovativesolutionsinthe
fieldsofarchitectureandplanning,inanefforttoaddressglobal
climatechange.”Itsfounder,NewMexicoarchitectEdwardMazria,
pointstodatafromtheU.S.EnergyInformationAdministration
thatindicatesbuildingsareresponsibleforalmosthalfthetotal
U.S.energyconsumptionandgreenhousegas(GHG)emissions
annually;globally,Mazriabelievesthepercentageisevengreater.
Whatisrelevanttoanydiscussionofsustainabledesignis
thatmostofthebuildingsector’senergyconsumptionisnot
attributabletotheproductionofmaterialsortheprocessof
construction,butrathertooperationalprocesses—theheating,
cooling,andlightingofbuildings.Thismeansthattoreducethe
energyconsumptionandGHGemissionsgeneratedbytheuseand
maintenanceofbuildingsovertheirlifespan,itisnecessaryto
properlydesign,site,andshapebuildingsandincorporatenatural
heating,cooling,ventilation,anddaylightingstrategies.
The2030ChallengeissuedbyArchitecture2030callsforall
newbuildingsanddevelopmentstobedesignedtousehalfthe
fossilfuelenergytheywouldtypicallyconsume,andthatanequal
amountofexistingbuildingareaberenovatedannuallytomeeta
similarstandard.Architecture2030isfurtheradvocatingthat
thefossilfuelreductionstandardbeincreasedfrom70%in2015
to80%in2020and90%in2025,andthatby2030,allnew
buildingsbecarbon-neutral(usingnofossil-fuelGHG-emitting
energytobuildandoperate).
Therearetwoapproachestoreducingabuilding’sconsumption
ofGHG-emittingfossilfuels.Thepassiveapproachistowork
withtheclimateindesigning,siting,andorientingabuildingand
employpassivecoolingandheatingtechniquestoreduceits
overallenergyrequirements.Theactiveapproachistoincrease
theabilityofabuildingtocaptureorgenerateitsownenergyfrom
renewablesources(solar,wind,geothermal,low-impacthydro,
biomass,andbio-gas)thatareavailablelocallyandinabundance.
Whilestrikinganappropriate,cost-effectivebalancebetween
energyconservationandgeneratingrenewableenergyisthegoal,
minimizingenergyuseisanecessaryfirststep,irrespectiveofthe
factthattheenergymaycomefromrenewableresources.
Residential:22.2%
Climate Change & Global Warming
Greenhousegases,suchascarbondioxide,methane,andnitrousoxide,
areemissionsthatriseintotheatmosphere.CO2 accountsforthe
largestshareofU.S.greenhousegasemissions.Fossilfuelcombustion
isthemainsourceofCO2 emissions.
1.Someoftheincomingsolarradiationisreflectedbytheearth
andtheatmospherebutmostoftheradiationisabsorbedand
warmstheearth’ssurfaceandatmosphere.
Industrial:31.4%
Transportation:27.8%
U.S. Energy Consumption by Sector
Source:2012DOEAnnualEnergyReview
4.Thedownwardpartof
thisinfraredradiationis
the“greenhouseeffect,”
raisingthetemperatureof
theloweratmosphereand
theearth’ssurface.
3.Whilesomeofthisinfrared
radiationpassesthroughthe
atmosphere,someisabsorbed
andre-emittedinalldirections
bygreenhousegasmoleculesand
watervaporintheatmosphere.
2.Theabsorbed
energyisthen
emittedfromthe
earth’ssurfaceas
long-waveinfrared
radiation.
Commercial:18.5%

17. SITE ANALYSIS 1.07
Siteanalysisistheprocessofstudyingthe
contextualforcesthatinfluencehowwemight
situateabuilding,layoutandorientitsspaces,
shapeandarticulateitsenclosure,andestablishits
relationshiptothelandscape.Anysitesurveybegins
withthegatheringofphysicalsitedata.
• Drawtheareaandshapeofthesiteasdefinedbyitslegalboundaries.
• Indicaterequiredsetbacks,existingeasements,andrights-of-way.
• Estimatetheareaandvolumerequiredforthebuildingprogram,site
amenities,andfutureexpansion,ifdesired.
• Analyzethegroundslopesandsubsoilconditionstolocatetheareas
suitableforconstructionandoutdooractivities.
• Identifysteepandmoderateslopesthatmaybeunsuitablefor
development.
• Locatesoilareassuitableforuseasadrainagefield,ifapplicable.
• Mapexistingdrainagepatterns.(LEEDSSCredits6.1,6.2:
StormwaterDesign)
• Determinetheelevationofthewatertable.
• Identifyareassubjecttoexcessiverunoffofsurfacewater,
flooding,orerosion.
• Locateexistingtreesandnativeplantmaterialsthatshouldbe
preserved.
• Chartexistingwaterfeatures,suchaswetlands,streams,watersheds,
floodplains,orshorelinesthatshouldbeprotected.(LEEDSSCredit
5.1:SiteDevelopment—ProtectorRestoreHabitat)
• Mapclimaticconditions:thepathofthesun,thedirectionof
prevailingwinds,andtheexpectedamountofrainfall.
• Considertheimpactoflandformsandadjacentstructuresonsolar
access,prevailingwinds,andthepotentialforglare.
• Evaluatesolarradiationasapotentialenergysource.
• Determinepossiblepointsofaccessfrompublicroadwaysandpublic
transitstops.(LEEDSSCredit4.1:AlternativeTransportation—
PublicTransportationAccess)
• Studypossiblecirculationpathsforpedestriansandvehiclesfrom
theseaccesspointstobuildingentrances.
• Ascertaintheavailabilityofutilities:watermains,sanitaryandstorm
sewers,gaslines,electricalpowerlines,telephoneandcablelines,and
firehydrants.
• Determineaccesstoothermunicipalservices,suchaspoliceandfire
protection.
• Identifythescopeofdesirableviewsaswellasobjectionableviews.
• Citepotentialsourcesofcongestionandnoise.
• Evaluatethecompatibilityofadjacentandproposedlanduses.
• Mapculturalandhistoricalresourcesthatshouldbepreserved.
• Considerhowtheexistingscaleandcharacteroftheneighborhood
orareamightaffectthebuildingdesign.
• Maptheproximitytopublic,commercial,medical,andrecreational
facilities.(LEEDSSCredit2:DevelopmentDensityandCommunity
Connectivity)

18. 1.08 SOILS
Therearetwobroadclassesofsoils—coarse-grainedsoilsandfine-grainedsoils.Coarse-
grainedsoilsincludegravelandsand,whichconsistofrelativelylargeparticlesvisibletothe
nakedeye;fine-grainedsoils,suchassiltandclay,consistofmuchsmallerparticles.The
AmericanSocietyforTestingandMaterials(ASTM)UnifiedSoilClassificationSystemfurther
dividesgravels,sands,silts,andclaysintosoiltypesbasedonphysicalcompositionand
characteristics.Seetablethatfollows.
Thesoilunderlyingabuildingsitemayactuallyconsistofsuperimposedlayers,each
ofwhichcontainsamixofsoiltypes,developedbyweatheringordeposition.Todepictthis
successionoflayersorstratacalledhorizons,geotechnicalengineersdrawasoilprofile,a
diagramofaverticalsectionofsoilfromthegroundsurfacetotheunderlyingmaterial,using
informationcollectedfromatestpitorboring.
Theintegrityofabuildingstructuredependsultimatelyonthestabilityandstrengthunder
loadingofthesoilorrockunderlyingthefoundation.Thestratification,composition,and
densityofthesoilbed,variationsinparticlesize,andthepresenceorabsenceofgroundwater
areallcriticalfactorsindeterminingthesuitabilityofasoilasafoundationmaterial.When
designinganythingotherthanasingle-familydwelling,itisadvisabletohaveageotechnical
engineerundertakeasubsurfaceinvestigation.
Asubsurfaceinvestigation(CSIMasterFormat™023200)involvestheanalysisandtesting
ofsoildisclosedbyexcavationofatestpitupto10'(3m)deeporbydeepertestboringsin
ordertounderstandthestructureofthesoil,itsshearresistanceandcompressivestrength,
itswatercontentandpermeability,andtheexpectedextentandrateofconsolidationunder
loading.Fromthisinformation,thegeotechnicalengineerisabletogaugetheanticipatedtotal
anddifferentialsettlementunderloadingbyaproposedfoundationsystem.
• Gravel • Sand • Clay
Soil Classification* Symbol Description Presumptive Bearing Capacity† Susceptibility Permeability
psf‡ kPa to Frost Action & Drainage
Gravels Cleangravels GW Well-gradedgravel 10000 479 None Excellent
6.4–76.2mm GP Poorlygradedgravel 10000 479 None Excellent
Gravelsw/fines GM Siltygravel 5000 239 Slight Poor
GC Clayeygravel 4000 192 Slight Poor
Sands Cleansands SW Well-gradedsand 7500 359 None Excellent
0.05–6.4mm SP Poorlygradedsand 6000 287 None Excellent
Sandsw/fines SM Siltysand 4000 192 Slight Fair
SC Clayeysand 4000 192 Medium Poor
Silts LL>50§ ML Inorganicsilt 2000 96 Veryhigh Poor
0.002–0.05mm CL Inorganicclay 2000 96 Medium Impervious
& Clays LL<50§ OL Organicsilt-clay Verypoor High Impervious
<0.002mm MH Elasticinorganicsilt 2000 96 Veryhigh Poor
CH Plasticinorganicclay 2000 96 Medium Impervious
OH Organicclayandsilt Verypoor Medium Impervious
Highlyorganicsoils Pt Peat Unsuitable Slight Poor
* BasedontheASTMUnifiedSoilClassificationSystem
† Consultageotechnicalengineerandthebuildingcodeforallowablebearingcapacities.
‡ 1psf=0.0479kPa
§ LL=liquidlimit:thewatercontent,expressedasapercentageofdryweight,atwhichasoilpassesfromaplastictoaliquidstate.

19. SOIL MECHANICS 1.09
Theallowablebearingcapacityofasoilisthemaximumunit
pressureafoundationispermittedtoimposeverticallyor
laterallyonthesoilmass.Intheabsenceofgeotechnical
investigationandtesting,buildingcodesmaypermittheuseof
conservativeload-bearingvaluesforvarioussoilclassifications.
Whilehigh-bearing-capacitysoilspresentfewproblems,low-
bearing-capacitysoilsmaydictatetheuseofacertaintypeof
foundationandloaddistributionpattern,andultimately,the
formandlayoutofabuilding.
Densityisacriticalfactorindeterminingthebearingcapacity
ofgranularsoils.TheStandardPenetrationTestmeasuresthe
densityofgranularsoilsandtheconsistencyofsomeclays
atthebottomofaborehole,recordingthenumberofblows
requiredbyahammertoadvanceastandardsoilsampler.
Insomecases,compaction,bymeansofrolling,tamping,or
soakingtoachieveoptimummoisturecontent,canincreasethe
densityofasoilbed.
Coarse-grainedsoilshavearelativelylowpercentageofvoid
spacesandaremorestableasafoundationmaterialthansilt
orclay.Claysoils,inparticular,tendtobeunstablebecause
theyshrinkandswellconsiderablywithchangesinmoisture
content.Unstablesoilsmayrenderasiteunbuildableunlessan
elaboratelyengineeredandexpensivefoundationsystemisput
inplace.
Theshearingstrengthofasoilisameasureofitsabilityto
resistdisplacementwhenanexternalforceisapplied,due
largelytothecombinedeffectsofcohesionandinternalfriction.
Onslopingsites,aswellasduringtheexcavationofaflatsite,
unconfinedsoilhasthepotentialtodisplacelaterally.Cohesive
soils,suchasclay,retaintheirstrengthwhenunconfined;
granularsoils,suchasgravel,sand,orsomesilts,requirea
confiningforcefortheirshearresistanceandhavearelatively
shallowangleofrepose.
Thewatertableisthelevelbeneathwhichthesoilissaturated
withgroundwater.Somebuildingsitesaresubjecttoseasonal
fluctuationsinthelevelofgroundwater.Anygroundwater
presentmustbedrainedawayfromafoundationsystemto
avoidreducingthebearingcapacityofthesoilandtominimize
thepossibilityofwaterleakingintoabasement.Coarse-grained
soilsaremorepermeableanddrainbetterthanfine-grained
soils,andarelesssusceptibletofrostaction.
•Compactclay
•Drysand
•Clay,silt,andsandmix
•Saturatedclay
Angle of Repose for Bare Soil Embankments

20. 1.10 TOPOGRAPHY
Topographyreferstotheconfigurationofsurfacefeatures
ofaplotofland,whichinfluenceswhereandhowtobuildand
developasite.Tostudytheresponseofabuildingdesigntothe
topographyofasite,wecanuseaseriesofsitesectionsora
siteplanwithcontourlines.
Contourlinesareimaginarylinesjoiningpointsofequal
elevationaboveadatumorbenchmark.Thetrajectoryofeach
contourlineindicatestheshapeofthelandformationatthat
elevation.Notethatcontourlinesarealwayscontinuousand
nevercrossoneanother;theycoincideinaplanviewonlywhen
theycutacrossaverticalsurface.
Contourintervalreferstothedifferenceinelevation
representedbyanytwoadjacentcontourlinesonatopographic
maporsiteplan.Theintervalusedisdeterminedbythescaleof
adrawing,thesizeofthesite,andthenatureofthetopography.
Thelargertheareaandthesteepertheslopes,thegreaterthe
intervalbetweencontours.Forlargeorsteeplyslopingsites,
20'or40'(5or10m)contourintervalsmaybeused.Forsmall
siteshavingrelativelygradualslopes,1',2',or5'(0.5or1.0m)
contoursmaybenecessary.
Wecandiscernthetopographicalnatureofasitebyreadingthe
horizontalspacingandshapeofcontourlines.
• Contoursspacedfarapartindicatearelativelyflat
orgentlyslopingsurface.
• Equallyspacedcontoursdenoteaconstantslope.
• Closelyspacedcontoursdisclosearelativelysteep
riseinelevation.
• Contourlinesrepresentaridgewhenpointingtoward
lowerelevations;theyrepresentavalleywhenpointing
towardhigherelevations.
• Groundslopesover25%aresubjecttoerosionand
aredifficulttobuildon.
• Groundslopesover10%arechallengingtousefor
outdooractivitiesandaremoreexpensivetobuildon.
• Groundslopesfrom5%to10%aresuitablefor
informaloutdooractivitiesandcanbebuiltonwithout
toomuchdifficulty.
• Groundslopesupto5%areusableformostoutdoor
activitiesandarerelativelyeasytobuildon.
• Slope(%)=[elevationgain(v)/horizontaldistance(h)]x100
Thegroundslopebetweenanytwocontourlinesisafunction
ofthetotalchangeinelevationandthehorizontaldistancebetween
thetwocontours.

21. Themicroclimateofasiteisinfluencedbythegroundelevation,
thenatureandorientationoflandforms,andthepresenceof
bodiesofwater.
• Solarradiationwarmssouthernslopes,creatinga
temperatezone.
• Daytimebreezes,whichreplaceupdraftsofwarmairover
land,canhaveacoolingeffectofupto10°F(5.6°C).
• Grassandothergroundcoverstendtolower
groundtemperaturesbyabsorbingsolarradiationand
encouragingcoolingbyevaporation.
• Hardsurfacestendtoelevategroundtemperatures.
• Light-coloredsurfacesreflectsolarradiation;darksurfaces
absorbandretaintheradiation.
Foraestheticandeconomic,aswellasecologicalreasons,thegeneral
intentindevelopingasiteshouldbetominimizethedisturbanceofexisting
landformsandfeatureswhiletakingadvantageofnaturalgroundslopesand
themicroclimateofthesite.
• Sitedevelopmentandconstructionshouldminimizedisruptingthe
naturaldrainagepatternsofthesiteandadjacentproperties.
• Whenmodifyinglandforms,includeprovisionsforthedrainage
ofsurfacewaterandgroundwater.
• Attempttoequalizetheamountofcutandfillrequired
forconstructionofafoundationandsitedevelopment.
• Avoidbuildingonsteepslopessubjecttoerosionorslides.
• Wetlandsandotherwildlifehabitatsmayrequireprotection
andlimitthebuildableareaofasite.
• Payparticularattentiontobuildingrestrictionsonsites
locatedinornearafloodplain.
• Elevatingastructureonpolesorpiersminimizes
disturbanceofthenaturalterrainandexistingvegetation.
• Terracingorsteppingastructurealongasloperequires
excavationandtheuseofretainingwallsorbenchterracing.
• Cuttingastructureintoaslopeorlocatingitpartially
undergroundmoderatestemperatureextremesandminimizesexposure
towind,andheatlossincoldclimates.
TOPOGRAPHY 1.11
CSI MasterFormat 31 10 00: Site Clearing
CSI MasterFormat 31 20 00: Earth Moving
CSI MasterFormat 32 70 00: Wetlands
Largebodiesofwater:
• Actasheatreservoirsandmoderatevariationsinlocaltemperature;
• Aregenerallycoolerthanlandduringthedayandwarmeratnight,
generatingoffshorebreezes;
• Aregenerallywarmerthanlandinwinterandcoolerinsummer.
• Inhot-dryclimates,evensmallbodiesofwateraredesirable,both
psychologicallyandphysically,fortheirevaporativecoolingeffect.
• Thetemperatureintheatmospheredecreases
withaltitude—approximately1°F(0.56°C)for
every400'(122m)inelevation.
• Warmairrises.
• Heaviercoolairsettles
intolow-lyingareas.
LEEDSSCredits7.1,7.2:HeatIslandEffect
LEEDSSCredit5.1:SiteDevelopment—
ProtectorRestoreHabitat
LEEDSSCredits6.1,6.2:StormwaterDesign

22. 1.12 PLANT MATERIALS
Plantmaterialsprovideaestheticaswellasfunctionalbenefitsin
conservingenergy,framingorscreeningviews,moderatingnoise,
retardingerosion,andvisuallyconnectingabuildingtoitssite.Factors
toconsiderintheselectionanduseofplantmaterialsinlandscaping
includethe:
• Treestructureandshape
• Seasonaldensity,texture,andcoloroffoliage
• Speedorrateofgrowth
• Matureheightandspreadoffoliage
• Requirementsforsoil,water,sunlight,andtemperaturerange
• Depthandextentoftherootstructure
• Treesandotherplantlifeadapttheirformstotheclimate.
• Existinghealthytreesandnativeplantmaterialsshouldbepreserved
wheneverpossible.Duringconstructionandwhenregradingasite,
existingtreesshouldbeprotectedforanareaequaltothediameter
oftheircrowns.Therootsystemsoftreesplantedtooclosetoa
buildingmaydisturbthefoundationsystem.Rootstructurescan
alsointerferewithundergroundutilitylines.
• Tosupportplantlife,asoilmustbeabletoabsorbmoisture,supply
theappropriatenutrients,becapableofaeration,andbefreeof
concentratedsalts.
Grassandothergroundcovers:
• Canreduceairtemperaturebyabsorbingsolarradiationand
encouragingcoolingbyevaporation;
• Aidinstabilizingsoilembankmentsandpreventingerosion;
• Increasethepermeabilityofsoiltoairandwater.
• Vinescanreducetheheattransmissionthroughasunlitwall
byprovidingshadeandcoolingtheimmediateenvironmentby
evaporation.
CSI MasterFormat 32 90 00: Planting
LEEDSSCredits6.1,6.2:StormwaterDesign
LEEDSSCredit7.1:HeatIslandEffect—Nonroof
LEEDWECredit1:WaterEfficientLandscaping

23. TREES 1.13
Providing Shade
Theamountofsolarradiationobstructedorfiltered
byatreedependsonits:
• Orientationtothesun
• Proximitytoabuildingoroutdoorspace
• Shape,spread,andheight
• Densityoffoliageandbranchstructure
• Treesshadeabuildingoroutdoorspacemosteffectivelyfrom
thesoutheastduringthemorningandthesouthwestduringthelate
afternoonwhenthesunhasalowaltitudeandcastslongshadows.
• South-facingoverhangsprovidemoreefficientshadingduring
themiddayperiodwhenthesunishighandcastsshortshadows.
• Deciduoustreesprovideshadeandglareprotectionduringthesummer
andallowsolarradiationtopenetratethroughtheirbranchstructures
duringthewinter.
• Evergreensprovideshadethroughouttheyearandhelpreducesnow
glareduringthewinter.
Serving as Windbreak
• Evergreenscanformeffectivewindbreaksandreduce
heatlossfromabuildingduringthewinter.
• Thefoliageofplantmaterialsreduceswind-blowndust.
Defining Space
• Treescanshapeoutdoorspacesforactivityandmovement.
Directing or Screening Views
• Treescanframedesirableviews.
• Treescanscreenundesirableviewsandprovideprivacyfor
outdoorspaces.
Attenuating Sound
• Acombinationofdeciduousandevergreentreesismosteffectivein
interceptingandattenuatingairbornesound,especiallywhencombined
withearthmounds.
Improving Air Quality
• Treestrapparticulatematterontheirleaves,whichisthenwashedto
thegroundduringrainfall.
• Leavescanalsoassimilategaseousandotherpollutants.
• Photosyntheticprocesscanmetabolizefumesandotherodors.
Stabilizing Soil
• Therootstructuresoftreesaidinstabilizingsoil,increasingthe
permeabilityofthesoiltowaterandair,andpreventingerosion.
Treesaffecttheimmediateenvironmentofabuildinginthefollowingways:

24. 1.14 SOLAR RADIATION
Thelocation,form,andorientationofabuildinganditsspaces
shouldtakeadvantageofthethermal,hygienic,andpsychological
benefitsofsunlight.Solarradiation,however,maynotalwaysbe
beneficial,dependingonthelatitudeandclimateofthesite.In
planningthedesignofabuilding,theobjectiveshouldbetomaintain
abalancebetweenunderheatedperiodswhensolarradiationis
beneficialandoverheatedperiodswhenradiationshouldbeavoided.
Thepathofthesunthroughtheskyvarieswiththeseasonsandthe
latitudeofabuildingsite.Therangeofsolaranglesforaspecificsite
shouldbeobtainedfromaweatheralmanacorservicebureaubefore
calculatingthepotentialsolarheatgainandshadingrequirements
forabuildingdesign.
• Horizon
• Summersolstice(June21)
• Springequinox(March21)
• Autumnalequinox(September22)
• Wintersolstice(December22)
• Altitudeistheangular
elevationofthesunabove
thehorizon.
• Azimuthistheangleofhorizontaldeviation,
measuredclockwise,ofabearingfroma
standardsouthdirection.
Solar Path Diagram
Representative Solar Angles
North Latitude Representative City Altitude at Noon Azimuth at Sunrise & Sunset*
Dec. 22 Mar. 21/Sept. 22 Dec. 22 June 21
48° Seattle 18° 42° 54° 124°
44° Toronto 22° 46° 56° 122°
40° Denver 26° 50° 58° 120°
36° Tulsa 30° 54° 60° 118°
32° Phoenix 34° 58° 62° 116°
*Azimuthiseastofsouthforsunrise,andwestofsouthforsunset.

25. SOLAR RADIATION 1.15
Thefollowingarerecommendedformsandorientationsfor
isolatedbuildingsindifferentclimaticregions.Theinformation
presentedshouldbeconsideredalongwithothercontextual
andprogrammaticrequirements.
Cool Regions
Minimizingthesurfaceareaofabuildingreducesexposureto
lowtemperatures.
• Maximizeabsorptionofsolarradiation.
• Reduceradiant,conductive,andevaporativeheatloss.
• Providewindprotection.
Temperate Regions
Elongatingtheformofabuildingalongtheeast-west
axismaximizessouth-facingwalls.
• Minimizeeastandwestexposures,whichare
generallywarmerinsummerandcoolerinwinterthan
southernexposures.
• Balancesolarheatgainwithshadeprotectionona
seasonalbasis.
• Encourageairmovementinhotweather;protectagainst
windincoldweather.
Hot-Arid Regions
Buildingformsshouldenclosecourtyardspaces.
• Reducesolarandconductiveheatgain.
• Promotecoolingbyevaporationusingwaterfeaturesand
plantings.
• Providesolarshadingforwindowsandoutdoorspaces.
Hot-Humid Regions
Buildingformelongatedalongtheeast-westaxisminimizes
eastandwestexposures.
• Reducesolarheatgain.
• Utilizewindtopromotecoolingbyevaporation.
• Providesolarshadingforwindowsandoutdoorspaces.
LEEDEACredit1:OptimizeEnergyPerformance
• Location
• Orientation
• Location
• Orientation
• Location
• Orientation
• Location
• Orientation

26. 1.16 PASSIVE SOLAR DESIGN
Passivesolarheatingreferstousingsolarenergytoheattheinterior
spacesofabuildingwithoutrelyingonmechanicaldevicesthat
requireadditionalenergy.Passivesolarsystemsrelyinsteadon
thenaturalheattransferprocessesofconduction,convection,and
radiationforthecollection,storage,distribution,andcontrolof
solarenergy.
• Thesolarconstantistheaveragerateatwhichradiantenergy
fromthesunisreceivedbytheearth,equalto
430Btupersquarefootperhour(1353W/m2/hr),usedin
calculatingtheeffectsofsolarradiationonbuildings.
Therearetwoessentialelementsineverypassivesolarsystem:
1. South-facingglassortransparentplasticforsolarcollection
• Areaofglazingshouldbe30%to50%offloorareaincold
climatesand15%to25%offloorareaintemperateclimates,
dependingonaverageoutdoorwintertemperatureandprojected
heatloss.
• Glazingmaterialshouldberesistanttothedegradationcaused
bytheultravioletraysofthesun.
• Double-glazingandinsulationarerequiredtominimizenighttime
heatloss.
2. Athermalmassforheatcollection,storage,anddistribution,
orientedtoreceivemaximumsolarexposure
• Thermalstoragematerialsincludeconcrete,brick,stone,tile,
rammedearth,sand,andwaterorotherliquid.
Phase-changematerials,suchaseuteticsaltsandparaffins,are
alsofeasible.
• Concrete:12"to18"(305to455)
• Brick:10"to14"(255to355)
• Adobe:8"to12"(200to305)
• Water:6"(150)ormore
• Dark-coloredsurfacesabsorbmoresolarradiation
thanlight-coloredsurfaces.
• Vents,dampers,movableinsulationpanels,andshadingdevices
canassistinbalancingheatdistribution.
Basedontherelationshipbetweenthesun,theinteriorspace,and
theheatcollectionsystem,therearethreewaysinwhichpassive
solarheatingcanbeaccomplished:directgain,indirectgain,and
isolatedgain.
CSI MasterFormat 23 56 00: Solar Energy Heating Equipment
LEEDEACredit2:On-SiteRenewableEnergy
LEEDEACredit6:GreenPower

27. PASSIVE SOLAR DESIGN 1.17
Direct Gain
Directgainsystemscollectheatdirectlywithinaninterior
space.Thesurfaceareaofthestoragemass,whichis
incorporatedintothespace,shouldbe50%to66%ofthe
totalsurfaceareaofthespace.Duringthecoolingseason,
operablewindowsandwallsareusedfornaturalorinduced
ventilation.
• Thermalfloorandwallmass
• Thermalmass:12"(305)Trombewallor6"(150)drumwall
• 10'x12'(3050x3660)orgreaterfloorarea
• Movableinsulationpanel
• Roofpond
• Ventforcooling
• Heatedmediumrises.
Indirect Gain
Indirectgainsystemscontrolheatgainattheexteriorskinofa
building.Thesolarradiationfirststrikesthethermalmass,either
aconcreteormasonryTrombewall,oradrumwallofwater-filled
barrelsortubes,whichislocatedbetweenthesunandtheliving
space.Theabsorbedsolarenergymovesthroughthewallby
conductionandthentothespacebyradiationandconvection.
Sunspace
Asunroomorsolariumisanothermediumforindirectheat
gain.Thesunspace,havingafloorofhighthermalmass,is
separatedfromthemainlivingspacebyathermalstoragewall
fromwhichheatisdrawnasneeded.Forcooling,thesunspace
canbeventedtotheexterior.
Roof Pond
Anotherformofindirectgainisaroofpondthatservesasaliquid
massforabsorbingandstoringsolarenergy.Aninsulatingpanel
ismovedovertheroofpondatnight,allowingthestoredheat
toradiatedownwardintothespace.Insummer,theprocessis
reversedtoallowinternalheatabsorbedduringthedaytoradiate
totheskyatnight.
Isolated Gain
Isolatedgainsystemscollectandstoresolarradiationaway
fromthespacetobeheated.Asairorwaterinacollectoris
warmedbythesun,itrisestotheservedspaceorisstored
inthethermalmassuntilneeded.Simultaneously,coolerair
orwaterispulledfromthebottomofthethermalstorage,
creatinganaturalconvectionloop.
• Ventforcooling
• Ventforcooling
• Ventforcooling
• Coolermediumfallsfor
reheating.
• Heatstorage

28. 1.18 SOLAR SHADING
Shadingdevicesshieldwindowsandotherglazedareasfrom
directsunlightinordertoreduceglareandexcessivesolar
heatgaininwarmweather.Theireffectivenessdependson
theirformandorientationrelativetothesolaraltitudeand
azimuthforthetimeofdayandseasonoftheyear.Exterior
devicesaremoreefficientthanthoselocatedwithininterior
spacesbecausetheyinterceptsolarraysbeforetheycanreach
anexteriorwallorwindow.
Illustratedarebasictypesofsolarshadingdevices.Theirform,
orientation,materials,andconstructionmayvarytosuit
specificsituations.Theirvisualqualitiesofpattern,texture,
andrhythm,andtheshadowstheycast,shouldbeconsidered
whendesigningthefacadesofabuilding.
CSI MasterFormat 10 71 13: Exterior Sun Control Devices
• Horizontaloverhangsaremosteffective
whentheyhavesouthernorientations.
• Horizontallouversparalleltoawallpermit
aircirculationnearthewallandreduce
conductiveheatgain.
• Louversmaybeoperatedmanuallyor
controlledautomaticallywithtimeor
photoelectriccontrolstoadapttothe
solarangle.
• Slantedlouversprovidemoreprotection
thanthoseparalleltoawall.
• Anglevariesaccordingtotherangeof
solarangles.
• Louvershungfromasolidoverhang
protectagainstlowsunangles.
• Louversmayinterferewithview.
• Verticallouversaremosteffectiveforeasternor
westernexposures.
• Louversmaybeoperatedmanuallyorcontrolled
automaticallywithtimeorphotoelectriccontrolsto
adapttosolarangle.
• Separationfromwallreducesconductiveheatgain.
• Eggcratescombinetheshadingcharacteristics
ofhorizontalandverticallouversandhaveahigh
shadingratio.
• Eggcrates,sometimesreferredtoas
brise-soleil,areveryefficientinhotclimates.
• Solarblindsandscreenscanprovideuptoa
50%reductioninsolarradiation,dependingon
theirreflectivity.
• Heat-absorbingglasscanabsorbupto40%of
theradiationreachingitssurface.
• Treesandadjacentstructuresmayprovideshadedepending
ontheirproximity,height,andorientation.

29. DAYLIGHTING 1.19
Solarradiationprovidesnotonlyheatbutalsolightfortheinterior
spacesofabuilding.Thisdaylighthaspsychologicalbenefitsaswellas
practicalutilityinreducingtheamountofenergyrequiredforartificial
lighting.Whileintense,directsunlightvarieswiththetimeofday,from
seasontoseason,andfromplacetoplace,itcanbediffusedbycloud
cover,haze,andprecipitation,andreflectedfromthegroundandother
surroundingsurfaces.
• Directsunlight
• Skylightreflectedanddiffusedbyairmolecules
• Externalreflectancefromthegroundandadjacentstructures
• Internalreflectancefromroomsurfaces
Thequantityandqualityofdaylightinginaspacearedeterminedby
thesizeandorientationofitswindowopenings,transmittanceof
theglazing,reflectanceofroomsurfacesandoutdoorsurfaces,and
obstructionsofoverhangsandnearbytrees.
• East-andwest-facingwindowsrequireshadingdevicestoavoidthe
brightearly-morningandlate-afternoonsun.
• South-facingwindowsareidealsourcesfordaylightifhorizontal
shadingdevicescancontrolexcessivesolarradiationandglare.
Thelevelofilluminationprovidedbydaylightdiminishesasitpenetrates
aninteriorspace.Generally,thelargerandhigherawindowis,themore
daylightwillenteraroom.
• Lightshelvesshadeglazingfromdirectsunlightwhilereflecting
daylightontotheceilingofaroom.Aseriesofparallel,opaquewhite
louverscanalsoprovidesolarshadingandreflectdiffuseddaylight
intotheinterior.
• Ausefulruleofthumbisthatdaylightingcanbeeffectivefortask
illuminationuptoadepthoftwicetheheightofawindow.
• Theceilingandbackwallofaspacearemoreeffectivethantheside
wallsorthefloorinthereflectionanddistributionofdaylight;light-
coloredsurfacesreflectanddistributelightmoreefficiently,butlarge
areasofshinysurfacescancauseglare.
• Skylightswithtranslucentglazingcaneffectivelydaylightaspace
fromabovewithoutexcessiveheatgain.
• Roofmonitorsareanothermeansofreflectingdaylightinto
aspace.
Excessivebrightnessratioscanleadtoglareandimpairmentofvisual
performance.Glarecanbecontrolledbytheuseofshadingdevices,the
properorientationoftasksurfaces,andallowingdaylighttoentera
spacefromatleasttwodirections.
• Placewindowsadjacenttosidewallsforadditionalreflectanceand
illumination.
• North-facingwindowsletin
soft,diffuseskylight.
• Forthemostbalanced
daylighting,allowdaylightto
penetrateaspacefromat
leasttwodirections.
LEEDIEQCredit8.1:DaylightandViews—Daylight

30. 1.20 PRECIPITATION
Theamountofannualandseasonalprecipitationexpectedfora
buildingsiteshouldinfluencethedesignandconstructionofthe
roofstructureofabuilding,thechoiceofbuildingmaterials,and
thedetailingofitsexteriorwallassemblies.Furthermore,therunoff
ofrainandmeltingsnowfromconstructedroofareasandpaved
surfacesincreasestheamountofstormwaterthatmustbedrained
fromthesite.
• Flatroofsrequireeitherinteriorroofdrainsorscuppersalong
theirperimeterfordrainage.Secondary,emergencyoverflowroof
drainsorscuppersarerequiredincaseswherewatermightbe
trappediftheprimaryroofdrainsareblocked.
• Incoldclimates,flatroofsaresubjecttoheavysnowloads.The
layerofsnowmayserveasadditionalinsulation.
• Cisternsforcollecting
rainwatermayserveasa
primaryorbackupsupplyof
water;rooftopcisternscan
imposeabove-normalgravity
loadsontheroofstructure.
• Moderatelypitchedroofseasilyshedrainbutmay
retainsnow.
• Overhangsprotecttheexteriorwallsofabuildingfrom
theweatheringeffectsofsunandrain.
• Steeplypitchedroofsshedrainwaterquickly.Iftheangle
oftheslopeisgreaterthan60°,theroofmayalsobeable
tosloughoffsnow.
• Guttersanddownspoutsleadtoastormsewerortoa
naturaloutfallonthesite.
• SeeChapter6forconstructingroofsystems.
• SeeChapter7forroofingassemblies.

31. SITE DRAINAGE 1.21
Developmentofasitecandisrupttheexistingdrainagepatternandcreate
additionalwaterflowfromconstructedroofareasandpavedsurfaces.
Limitingdisruptionofasite’snaturalwaterhydrologyandpromoting
infiltrationbysuchmeansasperviouspavingandvegetatedroofsis
advisable.Sitedrainageisnecessarytopreventerosionandthecollection
ofexcesssurfacewaterorgroundwaterresultingfromnewconstruction.
Therearetwobasictypesofsitedrainage:subsurfaceandsurface
drainagesystems.Subsurfacedrainageconsistsofanunderground
networkofpipingforconveyinggroundwatertoapointofdisposal,asa
stormsewersystemoranaturaloutfallatalowerelevationonthesite.
Excessgroundwatercanreducetheload-carryingcapacityofafoundation
soilandincreasethehydrostaticpressureonabuildingfoundation.
Waterproofingisrequiredforbasementstructuressituatedclosetoor
belowthewatertableofasite.
Surfacedrainagereferstothegradingandsurfacingofa
siteinordertodivertrainandothersurfacewaterinto
naturaldrainagepatternsoramunicipalstormsewersystem.Aholding
pondmaybenecessarywhentheamountofsurfacerunoffexceedsthe
capacityofthestormsewersystem.
CSI MasterFormat 32 70 00: Wetlands
CSI MasterFormat 33 40 00: Storm Drainage Utilities
• Acurtainorinterceptingdrainmaybeplaced
betweenasourceofgroundwaterandtheareatobe
protected.
• OnetypeofcurtaindrainisaFrenchdrain,which
consistsofatrenchfilledtogroundlevelwithloose
stonesorrockfragments.
Surface Drainage Slopes
• Grasslawnsandfields:1.5%to10%
recommended
• Pavedparkingareas:2%to3%recommended
• Swalesareshallowdepressionsformedbythe
intersectionoftwogroundslopes,designed
todirectordiverttherunoffofsurfacewater.
Vegetatedswalescanincreaseinfiltration.
• Grassswales:1.5%to2%recommended
• Pavedswales:4%to6%recommended
• Areadrainscollectsurfacewaterfromabasement
floororpavedarea.
• Drywellsaredrainagepitslinedwithgravelor
rubbletoreceivesurfacewaterandallowitto
percolateawaytoabsorbentearthunderground.
• Catchbasinsarereceptaclesfortherunoffof
surfacewater.Theyhaveabasinorsumpthat
retainsheavysedimentbeforeitcanpassintoan
undergrounddrainpipe.
• Culvertsaredrainsorchannelspassingundera
roadorwalkway.
• Finishgradesshouldbeslopedtodrainsurface
waterawayfromabuilding:5%minimum;2%
minimumforimpervioussurfaces.
• Groundwaterconsistslargelyofsurfacewater
thathasseepeddownthroughporoussoil.
• Foundationdrainsystem;see3.14.
• Catchmentareascanbedesignedtolooklikeand
functionaspondsandmarshes.
• Constructedwetlandsareengineered,designed,
andconstructedtoutilizenaturalprocessesin
treatingwastewaterandimprovingwaterquality.
LEEDSSCredits6.1,6.2:StormwaterDesign
LEEDWECredit2:InnovativeWastewaterTechnologies

32. 1.22 WIND
Thedirectionandvelocityofprevailingwindsareimportant
siteconsiderationsinallclimaticregions.Theseasonaland
dailyvariationsinwindshouldbecarefullyconsideredin
evaluatingitspotentialforventilatinginteriorspacesand
outdoorcourtyardsinwarmweather,causingheatlossincold
weather,andimposinglateralloadsonabuildingstructure.
Wind-inducedventilationofinteriorspacesaidsinthe
airexchangenecessaryforhealthandodorremoval.In
hotweather,andespeciallyinhumidclimates,ventilation
isbeneficialforconvectiveorevaporativecooling.Natural
ventilationalsoreducestheenergyrequiredbymechanical
fansandequipment.(LEEDIEQCredit2:IncreasedVentilation)
Themovementofairthroughabuildingisgeneratedby
differencesinairpressureaswellastemperature.Theresulting
patternsofairflowareaffectedmorebybuildinggeometryand
orientationthanbyairspeed.
Theventilationofconcealedroofandcrawlspacesisrequired
toremovemoistureandcontrolcondensation.Inhotweather,
atticventilationcanalsoreduceoverheadradiantheatgain.
Incoldclimates,abuildingshouldbebufferedagainstchilling
windstoreduceinfiltrationintointeriorspacesandlowerheat
loss.Awindbreakmaybeintheformofanearthberm,agarden
wall,oradensestandoftrees.Windbreaksreducewindvelocity
andproduceanareaofrelativecalmontheirleewardside.The
extentofthiswindshadowdependsontheheight,depth,and
densityofthewindbreak,itsorientationtothewind,andthe
windvelocity.
• Apartiallypenetrablewindscreencreateslesspressure
differential,resultinginalargewindshadowontheleeward
sideofthescreen.
Thestructure,components,andcladdingofabuildingmust
beanchoredtoresistwind-inducedoverturning,uplift,and
sliding.Windexertspositivepressureonthewindwardsurfaces
ofabuildingandonwindwardroofsurfaceshavingaslope
greaterthan30°.Windexertsnegativepressureorsuction
onthesidesandleewardsurfacesandnormaltowindward
roofsurfaceshavingaslopelessthan30°.See2.09formore
informationonwindforces.
• Flatroof • Roofslopesupto7:12 • Roofslopesgreaterthan7:12
• H=heightofwindbreak
2to5H
• Windwardshadow
10to15H
• Leewardwindshadow
• Pressureeddy • Suctioneddy
• Turbulentwake
• Outletsshouldbeaslarge
orlargerthaninletsfor
maximumairflow.
• Thepositionofanoutlethas
littleeffectontheairflow
patternbutshouldallowrising
warmairtoescape.
• Roofoverhangsincrease
incomingflowofair.
• Interiorpartitionsand
furnishingsmayadversely
alterairflowpatterns.
• Highpressure
• Highinletsdirectairflowupward,
resultinginalossofcoolingeffect.
• Lowinletsdirectair
flowatoccupants. • Lowpressure
• Louverscanbeneficiallyredirect
anddiffuseairflow.
• Slotsinoverhangsequalize
externalpressure.
• Overhangsoveropeningsdirectflow
upwardwhichmaybeundesirableforcooling.
• See7.47forthe
ventilationof
concealedspaces.

33. SOUND & VIEWS 1.23
Soundrequiresasourceandapath.Undesirableexterior
soundsornoisemaybecausedbyvehiculartraffic,aircraft,
andothermachinery.Thesoundenergytheygeneratetravels
throughtheairoutwardfromthesourceinalldirectionsin
acontinuouslyexpandingwave.Thissoundenergy,however,
lessensinintensityasitdispersesoverawidearea.Toreduce
theimpactofexteriornoise,therefore,thefirstconsideration
shouldbedistance—locatingabuildingasfarfromthenoise
sourceaspossible.Whenthelocationordimensionsofasite
donotmakethispossible,thentheinteriorspacesofabuilding
maybescreenedfromthenoisesourceinthefollowingways.
• Usebuildingzoneswherenoisecanbetolerated,forexample,
mechanical,service,andutilityareas,asabuffer.
• Employbuildingmaterialsandconstructionassemblies
designedtoreducethetransmissionofairborneand
structure-bornesound.
• Orientdoorandwindowopeningsawayfromthesourcesof
undesirablenoise.
• Placephysicalmass,suchasearthberms,betweenthenoise
sourceandthebuilding.
• Utilizedenseplantingsoftreesandshrubs,whichcanbe
effectiveindiffusingorscatteringsound.
• Plantgrassorothergroundcover,whichismoreabsorptive
thanthehard,reflectivesurfacesofpavements.
Animportantaspectofsiteplanningisorientingtheinterior
spacesofabuildingtotheamenitiesandfeaturesofa
site.Giventheappropriateorientation,windowopeningsin
thesespacesshouldbepositionednotonlytosatisfythe
requirementsfornaturallightandventilation,butalsotoreveal
andframedesirableviews.Dependingonthelocationofthe
site,theseviewsmaybecloseordistantinnature.Evenwhen
desirableviewsarenonexistent,apleasantoutlookcanoftenbe
createdwithinabuildingsitethroughlandscaping.
Awindowmaybecreatedwithinawallinanumberofways,
dependingonthenatureoftheviewandthewayitisframed
inthewallconstruction.Itisimportanttonotethatthesize
andlocationofwindowsalsoaffectthespatialqualityand
daylightingofaroom,andthepotentialforheatlossorgain.
• South-facingwindowscanbeeffectively
shadedwhileadmittingdaylight.
• North-facingwindowsareexposedto
winterwindsincoolclimates.
• East-andwest-facingwindowsaresources
ofoverheatingandaredifficulttoshadeeffectively.
• Expansiveview • Restrictedview • Filteredview
LEEDIEQCredit8.2:DaylightandViews—Views

34. 1.24 REGULATORY FACTORS
Zoningordinancesareenactedwithinamunicipalityor
land-usedistricttomanagegrowth,regulateland-usepatterns,
controlbuildingdensity,directdevelopmenttoareaswith
adequateservicesandamenities,protectenvironmentally
sensitiveareas,andconserveopenspace.
Foranysinglebuildingsite,azoningordinancewillregulateboth
thetypesofactivitythatmayoccuronitandthelocationandbulk
ofthebuildingorbuildingsconstructedtohousesuchactivities.A
specialtypeofzoningordinanceisthePlannedUnitDevelopment,
whichallowsafairlylargetractoflandtobedevelopedasasingle
entityforaddedflexibilityintheplacement,grouping,size,anduse
ofstructures.
Itisimportanttounderstandhowazoningordinancemight
constraintheallowablesizeandshapeofabuilding.Thebulkofa
buildingisregulateddirectlybyspecifyingvariousaspectsofits
size.
• Howmuchofthelandcanbecoveredbyabuildingstructureand
thetotalfloorareathatmaybeconstructedareexpressedas
percentagesofthelotarea.
• Themaximumwidthanddepthabuildingmayhaveare
expressedaspercentagesofthedimensionsofthesite.
• Zoningordinancesalsospecifyhowtallthebuildingstructure
canbe.
Thesizeandshapeofabuildingarealsocontrolledindirectlyby
specifyingtheminimumrequireddistancesfromthestructureto
thepropertylinesofthesiteinordertoprovideforair,light,solar
access,andprivacy.
Existingeasementsandrights-of-waymayfurtherlimitthe
buildableareaofasite.
• Aneasementisalegalrightheldbyonepartytomakelimited
useofthelandofanother,asforaright-of-wayorforaccessto
lightandair.
• Aright-of-wayisalegalrightgrantedtoasinglepartyor
thepublictotraverseanother’sland,asforaccesstoorthe
constructionandmaintenanceofutilitylines.
Alloftheaboverequirements,togetherwithanyrestrictionon
typeanddensityofuse,defineathree-dimensionalenvelope
beyondwhichthevolumeofabuildingmaynotextend.Refertothe
applicablezoningordinanceforspecificrequirements.
• Percentageofallowablelotcoverage=(CxD)/(AxB)
• Percentageofallowabletotalfloorarea=[(CxD)+(ExF)+(GxH)]/(AxB)
• Percentageofallowablewidthordepth=C/AorD/B
• Requiredfront,side,rearsetbacks
• Buildablearea
• Propertylines
LEEDSSCredit1:SiteSelection
LEEDSSCredit2:DevelopmentDensityandCommunityConnectivity

35. ZONING ORDINANCES 1.25
Exclusionstothegeneralrequirementsofazoningordinancemay
existintheformofexceptionsorallowances.Exceptionstothenormal
setbackrequirementsmaybemadefor:
• Projectionsofarchitecturalfeaturessuchasroof
overhangs,cornices,baywindows,andbalconies
• Accessorystructuressuchaslow-leveldecks,fences,
anddetachedcarportsorgarages
• Precedentssetbyexisting,neighboringstructures
Exceptionsareoftenmadeforslopingsites,orforsitesadjacentto
publicopenspaces.
• Slopingroofs,chimneys,andotherroofprojectionsmaybeallowedto
extendbeyondthenormalheightlimitation.
• Theheightlimitmaybedirectlyrelatedtotheslopeofasite.
• Areductioninthesetbackrequirementsmaybemadeforsloping
sitesorforsitesfrontingonopenspace.
Inordertoprovideforadequatelight,air,andspace,and
toenhancethestreetscapeandpedestrianenvironment,requirements
mayexistfor:
• Openspacesaccessibletothepublic
(LEEDSSCredit5.2:SiteDevelopment—MaximizeOpenSpace)
• Additionalsetbacksifastructurerisesaboveacertainheight
• Modulationofthefacadeofabuildingfrontingapublicspace
• Vehicularaccessandoff-streetparking
Zoningordinancesmayalsocontainrequirementsthatapplyonlyto
specificusecategoriesaswellasproceduresforrequestingavariance
fromtheregulations.
• Restrictivecovenantsareprovisionsinadeedthatrestrict
theactionofanypartytoit,asanagreementamongpropertyowners
specifyingtheusetowhichapropertycanbeput.Racialandreligious
restrictionsarelegallyunenforceable.
Otherregulatoryinstrumentsexistthataffectthewaybuildingsare
sitedandconstructed.Thesestatutes—commonlyreferredtoasthe
buildingcode—establishtherelationshipbetween:
• Thetypeofoccupancyabuildinghouses
• Thefire-resistanceratingofitsstructureandconstruction
• Theallowableheightandfloorareasofthebuilding,anditsseparation
fromneighboringstructures
• See2.05formoreinformationonbuildingcodes.
• Requiredsetback
• Possibleexceptions
• Possibleprojection
• Possiblereduction
forslope
•
Allowable
height
• Setback2
• Setback1
Height
1
Height
2

36. 1.26 SITE ACCESS & CIRCULATION
Providingforaccessandcirculationforpedestrians,automobiles,
andservicevehiclesisanimportantaspectofsiteplanning,
whichinfluencesboththelocationofabuildingonitssiteandthe
orientationofitsentrances.Outlinedhereandonthefollowing
pagesarefundamentalcriteriaforestimatingandlayingoutthe
spacerequiredforwalkways,roadways,andsurfaceparking.
1. Provideforsafeandconvenientpedestrianaccessand
movementtobuildingentrancesfromparkingareasorpublic
transitstopswithminimalcrossingofroadways.
2. Determinethenumberofparkingspacesrequiredbythezoning
ordinanceforthetypeofoccupancyandtotalnumberofunits
orfloorareaofthebuilding.
3. Determinethenumberofaccessibleparkingspacesas
wellascurbcuts,ramps,andpathstoaccessiblebuilding
entrancesrequiredbylocal,state,orfederallaw.
4. Provideloadingzonesforbusesandotherpublictransportation
vehicleswhereapplicable.
5. Separateserviceandtruckloadingareasfrompedestrianand
automobiletraffic.
6. Furnishaccessforemergencyvehiclessuchasfiretrucksand
ambulances.
7. Establishtherequiredwidthandlocationofcurbcutsandtheir
properdistancefrompublicstreetintersections.
8. Ensureclearsightlinesforvehiclesenteringpublicroadways.
9. Planforcontrolofaccesstoparkingareaswhererequired.
10.Providespaceforlandscaping;screeningofparkingareasmaybe
requiredbyzoningordinance.
11.Slopepavedwalkwaysandparkingareasfordrainage.
12.Providespaceforsnowremovalequipmentincoldclimates.
CSI MasterFormat 32 10 00: Bases, Ballasts, and Paving
CSI MasterFormat 32 30 00: Site Improvements
• Illustrationadaptedfromthesiteplanforthe
CarréHouse,designedbyAlvarAalto.

37. PEDESTRIAN CIRCULATION 1.27
• 7'-6"(2285)minimumoverheadclearance
• Minimizeconflictswithroadwaysandparkingareas.
• Providetractioninareassubjecttoicyconditions.
• 0.5%minimumslopefordrainage;1.5%preferred
Pedestrian Walks
• Minimumofthreerisersperrunofstairs
• Handrailsarerequiredforstairshavingfourormorerisers,
orwhereicyconditionsexist.
Exterior Stairs
• Provideamenities,suchasbenches,trashcontainers,and
lighting.
Bike Paths
• Avoidsurfaceirregularitiesthatcanimpedewheelchair
traffic.
• Providetactilewarningstripsforthevisuallyimpairedat
gradechangesandhazardousvehicularareas.
• SeeA.03forgeneralADAAccessibilityGuidelines.
ADA Accessibility Guidelines
• Curbrampsarerequiredwhereveranaccessible
routecrossesacurb.
• Surfaceoframpshouldbestable,firm,and
slip-resistant.
• Returnedcurbsareallowablewherepedestrians
wouldnotnormallywalkacrosstheramp.
Curb Ramps
• 3'(915)minimumfor
singlepathway
• 4'(1220)minimumfortwo
peoplewalkingsidebyside;6'to8'
(1830to2440)preferred
• 6'(1830)minimumwhen
adjacenttoparkingareawhere
carscanoverhangthewalkway
• 11"(280)minimumtreaddimension
• 4"(100)minimumriser;7"(180)maximumriser
• See9.03forproportioningstairdimensions.
• 4'(1220)minimumforone-way
traffic;5'(1525)preferred
• 7'(2135)minimumfortwo-waytraffic;
8'(2440)preferred
• 4'(1220)minimumfromtopoframp
tonearestobstruction
• 3'(915)minimumwidth
• 1:12maximumrampslope
• 1:10maximumslopeforflaredsides
• 1:20maximumcounterslope

38. 1.28 VEHICULAR CIRCULATION
OutsideTurningRadius
• Car:22'(6705)
• Ambulance:30'(9145)
• Bus:54'(16,460)
• Firetruck:48'(14,630)
• Semitruck/trailer:50'(15,240)
InsideTurningRadius
• Car:12'(3660)
• Ambulance:18'(5485)
• Bus:32'(9755)
• Firetruck:34'(10,365)
• Semitruck/trailer:28'(8535)
• 1:6maximumslope;1:10preferred
• Transitionslopeequaltoone-halfof
mainslope
Private Roadways
• 22'-0"(6705)
• 24'(7315)
• 11'(3355)minimum
Residential Drives and Garages
11'-8"(3555)
20'-10"(6350)
• 3'-0"(915)minimumfrom
wheelstoptowallorstorage
• 2'-6"(760)minimum
• Slopeslabfordrainage
• 7'(2135)
• 10'(3050)radius
• 8'-0"(2440)
minimum
17'-4"(5285)
minimum
• LoadingBerth:10'to12'
(3050to3660)wide;35'
to50'(10to15m)long
• 20'(6095)radius;
15'(4570)minimum
• Onelane:13'(3960);
10'(3050)minimum
• Twolanes:22'(6705);
18'(5485)minimum
• 15'(4570);
13'(3960)minimum
• 20'(6095)radius;
15'(4570)minimum
• 11'(3355)
merginglane
• 4'(1220)radius
• 20'(6095)radius;
15'(4570)minimum

39. VEHICULAR PARKING 1.29
• Local,state,andfederallawsregulatethe
numberofaccessiblespacesrequired.
• Locateaccessibleparkingspacesasclose
aspossibletobuildingorfacilityentrance.
• 1:50maximumslopeforspacesand
accessaisles
ADA Accessibility Guidelines
Vehicle Dimensions
• Compactcar:5'-8"x16'-0"(1725x4875)
• Standardcar:6'-6"x18'-0"(1980x5485)
Parking Spaces
• Standardcars:8'-6"to9'-0"(2590to2745)x
18'-0"to20'-0"(5485to6095)
• Compactcars:8'-0"(2440)x16'-0"(4875)
• Slope1%to5%fordrainage;
2%to3%recommended
18'-0"
(5485)
22'-0"
(6705)
18'-0"
(5485)
58'-0"
(18
m)
overall;
66'-0"
(20
m)
preferred
13'-6"
(4115)
22'-0"
(6705)
13'-6"
(4115)
54'-0"
(16
m)
overall;
58'-0"
(18
m)
preferred
Parking Lots
• 4'-0"(1220)radius
• Clearanceforwalkway
• 2'-6"(760)tocurborwheelstop
• Curborwheelstop
10'-4" 10'-4" 13'-0"
(3960) (3150) (3150)
• Wallline
• 2'-6"(760)
• Provideadditionalwidthfor
spaceprecedingcolumn
• 16%
• 8%
• 8%
• 8'(2440)minimumwidth
• 5'(1525)minimumaccessaisle;
maybesharedbytwoaccessible
parkingspaces.
• Identifyaccessibleparking
spaceswithasignshowing
theinternationalsymbolof
accessibility.
• Accessibleparkingspacesfor
vansusedbypersonswith
disabilitiesshouldhaveaclear
heightof9'-2"(2490)andan
accessaisleatleast8'(2440)
wide.
• Transitionslopeequaltoone-halfoframpslope;
10'(3050)length
Garage Ramps
• Accessaislesforparkingspaces
andpassengerloadingzones
shouldbepartoftheaccessible
routeoftraveltothebuildingor
facilityentrance.
• 5'(1525)minimumaccessaisle,
20'(6m)long,forpassenger
loadingzonesadjacentand
paralleltothevehiclepull-up
space.
• Widthofstructuralcolumn
• 7'-0"(2135)minimumoverheadclearance

40. 1.30 SLOPE PROTECTION
Slopesthataresubjecttoerosionfromtherunoffofsurfacewater
requiresomemeansofstabilization.Theneedforstabilizationcan
bereducedbydivertingtherunoffatthetopoftheslope,orby
creatingaseriesofterracestoreducethevelocityoftherunoff.
Theprincipalmechanicalmeansofprotectinganembankment
againsterosionisarevetmentofripraporgabions.
• Riprapisalayerofirregularlybrokenandrandom-sizedstones
placedontheslopeofanembankmenttopreventerosion.
• Depthoflayershouldbegreaterthanthemaximumsizeofstone.
• Filterfabricorgradedsandandgravelfordrainage
Cribbingorbinwallsmayalsobeusedtoholdbackandprotectsteep
embankments.
• Cribbingisacellularframeworkofsquaredsteel,concrete,or
timbermembers,assembledinlayersatrightangles,andfilled
withearthorstones.
• Abinwallisatypeofgravityretainingwallformedbystacking
modular,interlockingprecastconcreteunitsandfillingthevoids
withcrushedstoneorgravel.
• GabionsaregalvanizedorPVC-coatedwirebasketsfilledwith
stonesandstackedtoformanabutmentorretainingstructure,
orasripraptostabilizeanembankment.
• Filterfabricorgradedsandandgravelfordrainage
Naturalmeansofstabilizationincludesoilbinders—plant
materialsthatinhibitorpreventerosionbyprovidingagroundcover
andformingadensenetworkofrootsthatbindthesoil.
CSI MasterFormat 31 35 00: Slope Protection
CSI MasterFormat 31 36 00: Gabions
CSI MasterFormat 31 37 00: Riprap

41. RETAINING WALLS 1.31
Whenadesiredchangeingroundelevationexceedstheangleof
reposeofthesoil,aretainingwallbecomesnecessarytoholdback
themassofearthontheuphillsideofthegradechange.
Aretainingwallmustbedesignedandconstructedtoresistthe
lateralpressureofthesoilbeingretained.Thisactivepressure
increasesproportionallyfromzeroattheuppergradeleveltoa
maximumvalueatthelowestdepthofthewall.Thetotalpressure
orthrustmaybeassumedtobeactingthroughthecentroidofthe
triangulardistributionpattern,one-thirdabovethebaseofthewall.
• Surchargeisanadditionalload,asthatoftheearthabove
aretainingwall.Thelineofthrustparallelstheslopeofthe
surcharge.
• Assume33°fortheangleofreposeofmostsoils.
See1.09fortheangleofreposeforbaresoilembankments.
Aretainingwallmayfailbyoverturning,horizontalsliding,or
excessivesettling.
• Thrusttendstooverturnwallabouttoeofbase.
• Topreventaretainingwallfromoverturning,theresisting
moment(Mr)ofthecompositeweightofthewallandany
soilbearingontheheelofthebase(Wxd)mustcounterthe
overturningmoment(Mo)createdbythesoilpressure(TxH/3).
Usingasafetyfactorof2,Mr ≥2Mo.
• Topreventaretainingwallfromsliding,thecompositeweightof
thewalltimesthecoefficientoffrictionforthesoilsupporting
thewall(WxC.F.)mustcounterthelateralthrustonthewall(T).
Usingasafetyfactorof1.5,WxC.F.≥1.5T.
• Thepassivepressureofthesoilabuttingthelowerlevel ofthe
wallaidsinresistingthelateralthrust(T).
• Akeyalsoincreasestheresistanceofthewalltosliding.
• Averagecoefficientsoffriction:gravel,0.6;silt/dryclay,0.5;
sand,0.4;wetclay,0.3
• Topreventaretainingwallfromsettling,theverticalforce(W)
mustnotexceedthebearingcapacityofthesoil(B.C.),where
W=weightofthewallandanysoilbearingonthebaseplusthe
verticalcomponentofthesoilthrustforawallwithsurcharge.
Usingasafetyfactorof1.5,B.C.≥1.5W/A.
• T=totalpressureorthrust
• S=weightofretainedsoil;
100pcf(1600kg/m3)typical
• W=compositeweightofwallacting
throughcentroidofthesection
• R=resultantofTandW
• T=0.833xS(H+H')2/2
(foraretainingwallwithsurcharge)
• T=0.286xSH2/2
CSI MasterFormat 32 32 00: Retaining Walls

42. 1.32 RETAINING WALLS
Reinforced Concrete Retaining Walls
Theproportioningguidelinesbelowareforpreliminarydesignonly.
Consultastructuralengineerforfinaldesign,especiallywhena
retainingwallistobebuiltonpoorsoilorissubjecttosurchargeor
liveloads.
Gravity Wall
Agravityretainingwallresistsoverturningandslidingbythesheer
weightandvolumeofitsmass.Gravitywallsmaybeusedforretaining
structureslessthan10'(3048)high.
T-Type Cantilevered Wall
Cantileveredwallsofreinforcedconcreteareusedfor
retainingwallsupto20'(6095)high.Abovethisheight,counterfort
wallsareemployed.
Counterfort Wall
Acounterfortwallutilizestriangular-shapedcrosswallstostiffenthe
verticalslabandaddweighttothebase.Thecounterfortsarespaced
atregularintervalsequaltoone-halfthewallheight.
L-Type Cantilevered Wall
Thistypeofretainingwallisusedwhenthewallabutsapropertylineor
otherobstruction.
• Drainagesystemmayberequiredtorelievethebuildupofwater
pressurebehindthewall.
• Drainagematw/filterfabricorporousgravelbackfill
• 2"(51)øweepholes@4'–6'(1220–1830)o.c.,orperforated
drainpipeslopedtooutletawayfromwall
• 2"(51)minimum
• 3"(75)minimum
• Provideverticalcontroljoints@25'(7620)o.c.,andvertical
expansionjointseveryfourthcontroljoint.
CSI MasterFormat 32 32 13: Cast-in-Place Concrete Retaining Walls
0.5H
• 10"(255)
0.6H
(0.9Hw/surcharge)
• 8"(205)
• 0.7H
(1.25Hw/surcharge)
• 0.6H
(1.0Hw/surcharge)
• Footingshouldextendbelow
thefrostlineor2'(610)
belowthelowergradelevel,
whicheverisgreater.
• Batterreferstothe
backwardslopingfaceofa
wallasitrises,whichcan
offsettheillusionoftheface
leaningforward.
• Temperaturesteelforwalls
morethan10"(255)thick
• Structuralsteel
reinforcement

43. RETAINING WALLS 1.33
Timberandconcrete,brick,orstonemasonrymay
beusedforrelativelylowretainingwalls.
• 4x6or6x6pressure-treatedtimberslaidw/
overlappingjointsandspikedtogetherortiedw/
galvanizedsteelrods@4'-0"(1220)o.c.
Horizontal Timber Wall
• Brickorstonecoping
• Galvanizedwallties
• 4"(100)brickveneer
• 8"(205)concretemasonryunits
• 12"(305)concretemasonryunits
Brick Veneer Wall
• Batter
• Tiltstonesintoslopeforstability
• 6"(150)
Dry Stone Wall
CSI MasterFormat 32 32 19: Unit Masonry Retaining Walls
CSI MasterFormat 32 32 29: Timber Retaining Walls
• Provideawell-drained,
compactedgranularsubbase;
baseneednotextendtofrostline.
• Bottomofmortaredstonewalls
shouldextendbelowfrostline.
• Weepholes@4'–6'
(1220–1830)o.c.
• Perforateddrainpipesloped
tooutletawayfromwall
• Frostline
• 8"x24"(205x610)
concretefooting
• Horizontaltie
• Deadmanisatimber,
stone,orconcretemassburiedin
thegroundasananchor;usedfor
wallsover3'(915)highandplaced
6'-0"(1830)o.c.
• Graveldrainforwallsover2'(610)high
1'-4"(405)

44. 1.34 PAVING
Pavingprovidesawearingsurfaceforpedestrianorvehiculartrafficon
asite.Itisacompositestructurewhosethicknessandconstruction
aredirectlyrelatedtothetypeandintensityoftrafficandloadstobe
carried,andthebearingcapacityandpermeabilityofthesubgrade.
• Thepavementreceivesthetrafficwear,protectsthebase,and
transfersitsloadtothebasestructure.Therearetwotypesof
pavement:flexibleandrigid.
• Thebaseisafoundationofwell-gradedaggregatethattransfersthe
pavementloadtothesubgrade.Italsopreventstheupwardmigration
ofcapillarywater.Heavy-dutyloadsmayrequireanadditional
layer—asubbaseofcoarseraggregatesuchascrushedstone.
• Thesubgrade,whichmustultimatelycarrythepavementload,should
beundisturbedsoilorcompactedfill.Becauseitmayreceivemoisture
frominfiltration,itshouldbeslopedtodrain.
Flexiblepavements,consistingofconcrete,brick,orstoneunitpavers
laidonasandsettingbed,aresomewhatresilientanddistributeloads
tothesubgradeinaradiatingmanner.Theyrequirewood,steel,stone,
masonry,orconcreteedgingtorestrainthehorizontalmovementofthe
pavingmaterial.Speciallydesignedunitpaversmayqualifyaspermeable
orperviouspavingthatallowsrainfallandstormwatertopercolateto
anunderlyingreservoirbasewheretherunoffiseitherinfiltratedto
underlyingsoilsorremovedbyasubsurfacedrain.
Rigidpavements,suchasreinforcedconcreteslabsorpavingunits
mortaredoveraconcreteslab,distributetheirloadsinternally
andtransferthemtothesubgradeoverabroadarea.Theyrequire
reinforcementandanextensionofthebasematerialalongtheiredges.
Paving Materials
• Consultlocalsupplierforavailabilityofshapes,sizes,colors,textures,absorptionproperties,compressivestrength,andinstallationrecommendations.
• Brickpaver:4"x4",8",12";1"–2"thick
(100x100,205,305;25–57thick)
• Concreteunitpaver:12",18",24"square;11/2 "–3"
thick(305,455,610square;38–75thick)
• Interlockingpavers:21/2"–31/2"thick
(64–90thick)
• Gridorturfblock:31/2"thick
(90thick)
• Granitecobble:4"or6"square;6"thick
(100or150square;150thick)
• Cutstone:widthandlengthvaries;1"–2"thick
(25–51thick)
• 1%minimumslopefordrainage;highlytextured
pavingmayrequireasteeperslope.
CSI MasterFormat 32 10 00: Bases, Ballasts, and Paving
(LEEDSSCredits6.1,6.2:StormwaterDesign)

45. PAVING 1.35
• Unitpaversw/handtightsand-sweptjoints
• 1"–2"(25–51)sandsettingbed
• 2"–6"(51–150)compactedaggregate
whererequiredinhightrafficareasorover
expansivesoil
• Compactedsubgradeorundisturbedsoil
• Interlockingbasketweave
• Interlockingbasketweave
• Unitrunningbond
• Coursedashlar
Paving Patterns
Paving Details
• Pavingunitonmortarbed,
setonedgeorlaidflat
• Concretefooting;provide
gravelunderfootingiffrost
depthisdeeperthanfooting.
• Pavingunitsetvertically
onmortarbed;unitmay
extendupto1/2 ofpaver
heighttoformcurb.
• Concretefooting
• 2x,4x,or6xpressure-treated
woodedgeorcurb
• 2"(51)layerofwoodchips,
crushedstone,orpeagravel
• 2"(51)baseofsoil-cement
mixtureorcrushedstone
• 2x2or2x4pressure-treated
woodstakes,24"(610)long,
@3'to4'(915to1220)o.c.
• Turfblock
• Topsoilmixforgrassorgroundcover
• 2"(51)sandsettingbed
• 2"–6"(51–150)compactedaggregate
• Brickorconcretepavers
• 3/4"(19)bituminoussettingbed
• 4"to6"(100to150)concreteslab
• Compactedaggregate,ifrequired
Flexible Base
Rigid Base
Edge Conditions
• Interlockingherringbone
• Unitbasketweave
• Stackbond • Romancobble
• Randomstone
• Octagonanddot
• Turfblock
• Unitherringbone

46. 1.36 THE SITE PLAN
Thesiteplanillustratestheexistingnaturalandbuiltfeaturesof
asiteanddescribesproposedconstructioninrelationtothese
existingfeatures.Usuallybasedonanengineer’slandsurvey,the
siteplanisanessentialpieceofasetofconstructiondocuments.
Acompletedsiteplanshouldincludethefollowingitems:
1. Nameandaddressofpropertyowner
2. Addressofproperty,ifdifferentfromowner’saddress
3. Legaldescriptionofproperty
4. Sourceanddateoflandsurvey
5. Descriptionofthesiteboundaries:dimensionsofproperty
lines,theirbearingrelativetonorth,anglesofcorners,andradii
ofcurves
6. Contractorprojectlimits,ifdifferentfromsiteboundaries
7. Northarrowandscaleofdrawing
8. Locationanddescriptionofbenchmarksthatestablish
thereferencepointsforthelocationandelevationsofnew
construction
9. Identificationanddimensionsofadjacentstreets,alleys,and
otherpublicrights-of-way
10.Locationanddimensionsofanyeasementsor
rights-of-waythatcrossthesite
11.Dimensionsofsetbacksrequiredbythezoningordinance
12.Locationandsizeofexistingstructuresandadescriptionof
anydemolitionrequiredbythenewconstruction
13.Location,shape,andsizeofstructuresproposed
forconstruction,includingroofoverhangsandother
projections
14.Locationanddimensionsofexistingandproposedpaved
walkways,drives,andparkingareas
15.Locationofexistingutilities:watermains,sanitaryandstorm
sewers,gaslines,electricalpowerlines,telephoneandcable
lines,firehydrants,aswellasproposedpointsofconnections
16.Existingcontourlines,newcontourlinesandthefinishgrades
ofdrives,walks,lawns,orotherimprovedsurfacesafter
completionofconstructionorgradingoperations
17.Existingplantmaterialstoremainandthosetoberemoved
18.Existingwaterfeatures,suchasdrainageswales,creeks,flood
plains,watersheds,orshorelines
19.Proposedlandscapingfeatures,suchasfencing,retaining
walls,andplantings;ifextensive,landscapingandothersite
improvementsmaybeshownonaseparatesiteplan.
20.Referencestorelateddrawingsanddetails
SITE PLAN
Scale

47. THE SITE PLAN 1.37

48. 1.38 SITE DESCRIPTION
Alegaldescriptionofasiteconsistsofthelocation
andboundariesofaspecificparcelofland,basedona
metes-and-boundssurveyorarectangularsystemof
survey,ormadewithreferencetoarecordedplat.
• Ametes-and-boundssurveycallsoutthecourse
andlengthofeachboundarylineofaparcelofland,
startingataknownreferencepointandworking
aroundtheperipheryoftheplatuntilreturningtothe
placeofbeginning.
• Asurveyplatisalegaldocumentdescribingthe
location,boundaries,anddimensionsofatract
orparcelofland,includingzoningandplanning
commissionapprovals,easementsandrestrictions,
and,forasubdivision,thedividinglinesofstreet,
blocks,andlots,andthenumberinganddimensions
ofeachlot.
• Therectangularsystemofsurveyisbasedona
modifiedgridofnorth-southprincipalandguide
meridiansandeast-westbaselines.
• Rangeisoneofaseriesofdivisionsnumberedeast
orwestfromaguidemeridianandconsistingofarow
oftownshipsthatarenumberednorthorsouthfrom
abaseline.
• Townshipisaunitoflandarea,approximatelysix
milessquare(93.2km2)containing36sections.
• Sectionisoneofthe36numberedsubdivisions
ofatownship,eachapproximatelyonesquaremile
(2.59km2 or640acres)andfurthersubdivided
intohalves,quarters,andquarter-quarters.
• Principalmeridiansarenorth-south
referencelinesestablishedat
substantiallandmarksforlarge
areasofland.
• Guidemeridiansarenorth-south
referencelineslocatedbetween
correctionlinesat24-mile
(38.62-km)intervalstotheeast
andwestofprincipalmeridians.
• Rangelinesarenorth-south
referencelineslocatedat6-mile
(9.66-km)intervalsbetween
guidemeridians.
• East-westbaseline
• Correctionlinesareeast-west
referencelineslocatedat24-mile
(38.62-km)intervalstothenorth
andsouthofabaselinetocorrect
fortheconvergenceofmeridians
andequalizeeast-westdistances.
CSI MasterFormat 02 21 13: Site Surveys

49. THE BUILDING
2
2.02 The Building
2.03 Building Systems
2.05 Building Codes
2.06 Types of Construction
2.07 Occupancy Classification
2.08 Loads on Buildings
2.09 Wind Loads
2.10 Earthquake Loads
2.11 Structural Forces
2.12 Structural Equilibrium
2.13 Columns
2.14 Beams
2.15 Beam Spans
2.16 Trusses
2.17 Frames & Walls
2.18 Plate Structures
2.19 Structural Units
2.20 Structural Spans
2.21 Structural Patterns
2.22 Lateral Stability
2.24 High-Rise Structures
2.25 Arches & Vaults
2.26 Domes
2.27 Shell Structures
2.28 Cable Structures
2.29 Membrane Structures
2.30 Joints & Connections

50. 2.02 THE BUILDING
Architectureandbuildingconstructionarenotnecessarily
oneandthesamething.Anunderstandingofthemethods
forassemblingvariousmaterials,elements,andcomponents
isnecessaryduringboththedesignandtheconstruction
ofabuilding.Thisunderstanding,however,whileitenables
onetobuildarchitecture,doesnotguaranteeit.Aworking
knowledgeofbuildingconstructionisonlyoneofseveral
criticalfactorsintheexecutionofarchitecture.Whenwe
speakofarchitectureastheartofbuilding,weshouldconsider
thefollowingconceptualsystemsoforderinadditiontothe
physicalonesofconstruction:
• Thedefinition,scale,proportion,andorganizationofthe
interiorspacesofabuilding
• Theorderingofhumanactivitiesbytheirscaleand
dimension
• Thefunctionalzoningofthespacesofabuildingaccording
topurposeanduse
• Accesstothehorizontalandverticalpathsofmovement
throughtheinteriorofabuilding
• Thesensiblequalitiesofabuilding:form,space,light,color,
texture,andpattern
• Thebuildingasanintegratedcomponentwithinthenatural
andbuiltenvironment
Ofprimaryinteresttousinthisbookarethephysicalsystems
thatdefine,organize,andreinforcetheperceptualand
conceptualorderingofabuilding.
Asystemcanbedefinedasanassemblyofinterrelatedor
interdependentpartsformingamorecomplexandunified
wholeandservingacommonpurpose.Abuildingcanbe
understoodtobethephysicalembodimentofanumberof
systemsandsubsystemsthatmustnecessarilyberelated,
coordinated,andintegratedwitheachotheraswellaswith
thethree-dimensionalformandspatialorganizationofthe
buildingasawhole.

51. BUILDING SYSTEMS 2.03
Structural System
Thestructuralsystemofabuildingisdesignedand
constructedtosupportandtransmitappliedgravityand
lateralloadssafelytothegroundwithoutexceedingthe
allowablestressesinitsmembers.
• Thesuperstructureistheverticalextensionofabuilding
abovethefoundation.
• Columns,beams,andloadbearingwallssupportfloorand
roofstructures.
• Thesubstructureistheunderlyingstructureforming
thefoundationofabuilding.
Enclosure System
Theenclosuresystemistheshellorenvelopeofabuilding,
consistingoftheroof,exteriorwalls,windows,anddoors.
• Theroofandexteriorwallsshelterinteriorspacesfrom
inclementweatherandcontrolmoisture,heat,andair
flowthroughthelayeringofconstructionassemblies.
• Exteriorwallsandroofsalsodampennoiseandprovide
securityandprivacyfortheoccupantsofabuilding.
• Doorsprovidephysicalaccess.
• Windowsprovideaccesstolight,air,andviews.
• Interiorwallsandpartitionssubdividetheinterior
ofabuildingintospatialunits.
Mechanical Systems
Themechanicalsystemsofabuildingprovideessential
servicestoabuilding.
• Thewatersupplysystemprovidespotablewaterfor
humanconsumptionandsanitation.
• Thesewagedisposalsystemremovesfluidwasteand
organicmatterfromabuilding.
• Heating,ventilating,andair-conditioningsystems
conditiontheinteriorspacesofabuildingforthe
environmentalcomfortoftheoccupants.
• Theelectricalsystemcontrols,meters,andprotects
theelectricpowersupplytoabuilding,anddistributes
itinasafemannerforpower,lighting,security,and
communicationsystems.
• Verticaltransportationsystemscarrypeopleandgoods
fromoneleveltoanotherinmedium-and
high-risebuildings.
• Fire-fightingsystemsdetectandextinguishfires.
• Structuresmayalsorequirewastedisposaland
recyclingsystems.
Roof Systems
Chapter6
Moisture & Thermal
Protection
Chapter7
Floor Systems
Chapter4
Special Construction
Chapter9
Doors & Windows
Chapter8
Mechanical &
Electrical Systems
Chapter11
Wall Systems
Chapter5
Finish Work
Chapter10
Foundation Systems
Chapter3
The Building Site
Chapter1
Notes on Materials
Chapter12
UNIFORMAT II Group A: Substructure
UNIFORMAT II Group E: Equipment & Furnishings
UNIFORMAT II Group D: Services
UNIFORMAT II Group C: Interiors
UNIFORMAT II Group B: Shell

52. 2.04 BUILDING SYSTEMS
Themannerinwhichweselect,assemble,andintegratethevariousbuilding
systemsinconstructionshouldtakeintoaccountthefollowingfactors:
Performance Requirements
• Structuralcompatibility,integration,andsafety
• Fireresistance,prevention,andsafety
• Allowableordesirablethicknessofconstructionassemblies
• Controlofheatandairflowthroughbuildingassemblies
• Controlofmigrationandcondensationofwatervapor
• Accommodationofbuildingmovementduetosettlement,
structuraldeflection,andexpansionorcontractionwithchanges
intemperatureandhumidity
• Noisereduction,soundisolation,andacousticalprivacy
• Resistancetowear,corrosion,andweathering
• Finish,cleanliness,andmaintenancerequirements
• Safetyinuse
Aesthetic Qualities
• Desiredrelationshipofbuildingtoitssite,adjacentproperties,
andneighborhood
• Preferredqualitiesofform,massing,color,pattern,texture,anddetail
Regulatory Constraints
• Compliancewithzoningordinancesandbuildingcodes
Economic Considerations
• Initialcostcomprisingmaterial,transportation,equipment,
andlaborcosts
• Life-cyclecosts,whichincludenotonlyinitialcost,butalsomaintenance
andoperatingcosts,energyconsumption,usefullifetime,demolitionand
replacementcosts,andinterestoninvestedmoney
Environmental Impact
• Conservationofenergyandresourcesthroughsiting
andbuildingdesign
• Energyefficiencyofmechanicalsystems
• Useofresource-efficientandnontoxicmaterials
• See1.03–1.06
Construction Practices
• Safetyrequirements
• Allowabletolerancesandappropriatefit
• Conformancetoindustrystandardsandassurance
• Divisionofworkbetweentheshopandthefield
• Divisionoflaborandcoordinationofbuildingtrades
• Budgetconstraints
• Constructionequipmentrequired
• Erectiontimerequired
• Provisionsforinclementweather
• TheU.S.OccupationalHealth
andSafetyAct(OSHA)
regulatesthedesignof
workplacesandsetssafety
standardsunderwhichabuilding
mustbeconstructed.

53. BUILDING CODES 2.05
Buildingcodesareadoptedandenforcedbylocalgovernmentagencies
toregulatethedesign,construction,alteration,andrepairofbuildings
inordertoprotectthepublicsafety,health,andwelfare.Thecodes
generallyestablishrequirementsbasedonthetypeofoccupancy
andconstructionofabuilding,minimumstandardsformaterials
andmethodsofconstruction,andspecificationsforstructuraland
firesafety.Whilecodesareprimarilyprescriptiveinnature,theyalso
containperformancecriteria,stipulatinghowaparticularcomponent
orsystemmustfunctionwithoutnecessarilygivingthemeanstobe
employedtoachievetheresults.Thecodesoftenreferencestandards
establishedbytheAmericanSocietyforTestingandMaterials(ASTM),
theAmericanNationalStandardsInstitute(ANSI),andothertechnical
societiesandtradeassociations,toindicatethepropertiesdesired
inamaterialorcomponentandthemethodsoftestingrequiredto
substantiatetheperformanceofproducts.
Model Codes
Modelcodesarebuildingcodesdevelopedbynationalorganizationsof
codeofficials,materialsandlifesafetyexperts,professionalsocieties,
andtradeassociationsforadoptionbylocalcommunitiesaslegally
enforceableregulations.Ifcertainprovisionsneedtobemodifiedor
addedtoaddresslocalrequirementsorconcerns,amodelcodemaybe
enactedbyamunicipalitywithamendments.
International Building Code®
Sincetheearlypartofthelastcentury,threemajormodelcodeshave
beendevelopedforuseinvariouspartsoftheU.S.bytheBuilding
OfficialsandCodeAdministratorsInternational,Inc.(BOCA),the
InternationalConferenceofBuildingOfficials(ICBO),andtheSouthern
BuildingCodeConference(SBCC).In1994,thesemodel-codegroups
mergedtoformtheInternationalCodeCouncil(ICC)withthegoalof
developingacomprehensiveandcoordinatedsetofnationalmodel
codes.In2000,theICCpublishedthefirsteditionoftheInternational
Building Code® (IBC).
Aswiththemodelcodesthatprecededit,theIBCbeginsbydefining
categoriesofuseoroccupancyandsettingheightandarealimitations
inrelationtotheoccupancyofabuildingandthetypeofconstruction
employed,andthenprescribesfivetypesofconstructionaccording
todegreeoffireresistanceandcombustibility.Thecodealsocontains
provisionsforinteriorfinishes,fireprotectionsystems,emergency
egress,accessibility,interiorenvironment,energyefficiency,exterior
wallsandroofs,structuraldesign,buildingmaterials,elevatorsand
conveyingsystems,andexistingstructures.
Companion Codes
TheInternational Residential Code® (IRC)regulatestheconstructionofdetachedone-andtwo-
familydwellingsandtownhousesnotmorethanthreestoriesinheightandhavingaseparate
meansofegress.TheInternational Existing Building Code®,whichregulatesthealteration,
repair,andrenovationofexistingfacilities,emergedwiththeincreasingimportanceofhistoric
preservationandsustainablereuseofexistingbuildings.Othercompanioncodesincludethe
International Energy Conservation Code®,International Fire Code®,International Mechanical
Code®,andInternational Plumbing Code®.
Other Important Codes
TheNationalFireProtectionAssociation(NFPA)hasdevelopedanewmodelbuildingcode,NFPA
5000,asanalternativetotheInternational Building Code.TheNFPAalsopublishesothercode
documents.
• NFPA-70,theNational Electric Code,ensuresthesafetyofpersonsandthesafeguardingof
buildingsandtheircontentsfromhazardsarisingfromtheuseofelectricityforlight,heat,
andpower.
• NFPA-101,theLife Safety Code,establishesminimumrequirementsforfiresafety,the
preventionofdangerfromfire,smokeandgases,firedetectionandalarmsystems,fire
extinguishingsystems,andemergencyegress.
• NFPA-13governstheinstallationoffiresprinklers.
Federal Requirements
Inadditiontothelocallyadoptedversionofthemodelcodes,therearespecificfederal
requirementsthatmustbeconsideredinthedesignandconstructionoffacilities.
• TheAmericans with Disabilities Act (ADA)of1990isfederalcivil-rightslegislationrequiring
thatbuildingsbemadeaccessibletopersonswithphysicaldisabilitiesandcertaindefined
mentaldisabilities.TheADA Accessibility Guidelines (2010 ADA Standards for Accessible
Design)aremaintainedbytheU.S.AccessBoard,anindependentgovernmentalagency,and
theregulationsareadministeredbytheU.S.DepartmentofJustice.Federalfacilitiesmust
complywithstandardsissuedundertheArchitectural Barriers Act (ABA).Initslastupdate,
theAccessBoardharmonizedtheADAguidelineswithitsguidelinesforfacilitiescoveredby
theABAandpublishedthemjointlyastheADA-ABA Accessibility Guidelines.Inaddition,the
BoardandtheInternationalCodeCouncil(ICC)workedcooperativelytocoordinatetheADA
andABAguidelinesandaccessprovisionsintheInternational Building Code.
• TheFederalFairHousingAct(FFHA)of1988includesDepartmentofHousingandUrban
Development(HUD)regulationsrequiringallresidentialcomplexesoffourormoredwelling
unitsconstructedafterMarch13,1991tobeadaptableforusebypersonswithdisabilities.
Type of Construction
• See2.06
Maximum Height & Area
Occupancy or Use
• See2.07

54. 2.06 TYPES OF CONSTRUCTION
TheIBCclassifiestheconstructionofabuildingaccordingtothe
fireresistanceofitsmajorelements:structuralframe,exteriorand
interiorbearingwalls,nonbearingwallsandpartitions,andfloorand
roofassemblies.
• TypeIbuildingshavetheirmajorbuildingelementsconstructedof
noncombustiblematerials,suchasconcrete,masonry,orsteel.
Somecombustiblematerialsmaybeallowediftheyareancillaryto
theprimarystructureofthebuilding.TypeIIbuildingsaresimilar
toTypeIbuildingsexceptforareductionintherequiredfire-
resistanceratingsofthemajorbuildingelements.
• TypeIIIbuildingshavenoncombustibleexteriorwallsandmajor
interiorelementsofanymaterialpermittedbythecode.
• TypeIVbuildings(HeavyTimber,HT)havenoncombustibleexterior
wallsandmajorinteriorelementsofsolidorlaminatedwoodof
specifiedminimumsizesandwithoutconcealedspaces.
• TypeVbuildingshavestructuralelementsandexteriorandinterior
wallsofanymaterialpermittedbythecode.
• TypeV-Protectedconstructionrequiresallmajorbuildingelements,
exceptfornonbearinginteriorwallsandpartitions,tobeofone-
hourfire-resistiveconstruction.
• TypeV-Unprotectedconstructionhasnorequirementsforfire-
resistanceexceptforwhenthecoderequiresprotectionofexterior
wallsduetheirproximitytoapropertylineortoadjacentbuildings
onthesamesite.
• Thetablebelowoutlinestherequiredfire-resistiveratingsofmajor
buildingelementsforthevarioustypesofconstruction.Consult
Table601oftheInternational Building Code formorespecific
requirements.
• SeeAppendixforthefire-resistanceratingsofrepresentative
constructionassemblies.
Fire-Resistance Rating Requirements (hours)
Construction Type Type I Type II Type III Type IV Type V
A B A B A B HT A B
Building Element
Structuralframe 3 2 1 0 1 0 HT 1 0
Bearingwalls
Exterior 3 2 1 0 2 2 2 1 0
Interior 3 2 1 0 1 0 1/HT 1 0
Nonbearingwalls Varieswithoccupancy,typeofconstruction,locationonpropertyline,anddistancetoadjacentstructures
Floorconstruction 2 2 1 0 1 0 HT 1 0
Roofconstruction 11/2 1 1 0 1 0 HT 1 0

55. OCCUPANCY CLASSIFICATION 2.07
TheIBClimitsthemaximumheightandareaperfloorofabuilding
accordingtoconstructiontypeandoccupancygroup,expressingthe
intrinsicrelationshipbetweendegreeoffireresistance,sizeofabuilding,
andnatureofanoccupancy.Thelargerabuilding,thegreaterthenumber
ofoccupants,andthemorehazardoustheoccupancy,themorefire-
resistantthefacilityshouldbe.Theintentistoprotectabuildingfromfire
andtocontainafirelongenoughforthesafeevacuationofoccupantsand
forafirefightingresponsetooccur.Thelimitationonsizemaybeexceeded
ifthebuildingisequippedwithanautomaticfiresprinklersystem,orifit
isdividedbyfirewallsintoareasnotexceedingthesizelimitation.
• Firewallsarerequiredtohaveafire-resistanceratingsufficientto
preventthespreadoffirefromonepartofabuildingtoanother.They
mustextendinacontinuousmannerfromthefoundationtoaparapet
abovetheroofofabuilding,ortotheundersideofanoncombustible
roof.Allopeningsinfirewallsarerestrictedtoacertainpercentage
ofthewalllengthandmustbeprotectedbyself-closingfiredoors,
fire-ratedwindowassemblies,and,inthecaseofairducts,byfireand
smokedampers.
• Occupancyseparationsrefertofire-resistiveverticalorhorizontal
constructionsrequiredtopreventthespreadoffirefromone
occupancytoanotherinamixed-occupancybuilding.
• Fireseparationdistancereferstothespacerequiredbetweena
propertylineoradjacentbuildingandanexteriorwallhavingaspecified
fire-resistancerating.
Examples of Occupancy Classifications
A Assembly
Auditoriums,theaters,andstadiums
B Business
Offices,laboratories,andhighereducationfacilities
E Educational
Child-carefacilitiesandschoolsthroughthe12thgrade
F Factories
Fabricating,assembling,ormanufacturingfacilities
H Hazardous uses
Facilitieshandlingacertainnatureandquantityofhazardousmaterials
I Institutional
Facilitiesforsupervisedoccupants,suchashospitals,nursinghomes,andreformatories
M Mercantile
Storesforthedisplayandsaleofmerchandise
R Residential
Homes,apartmentbuildings,andhotels
S Storage
Warehousingfacilities

56. 2.08 LOADS ON BUILDINGS
Inenclosingspaceforhabitation,thestructuralsystemofabuilding
mustbeabletosupporttwotypesofloads—staticanddynamic.
Static Loads
Staticloadsareassumedtobeappliedslowlytoastructureuntil
itreachesitspeakvaluewithoutfluctuatingrapidlyinmagnitudeor
position.Underastaticload,astructurerespondsslowlyandits
deformationreachesapeakwhenthestaticforceismaximum.
• Liveloadscompriseanymovingormovableloadsonastructure
resultingfromoccupancy,collectedsnowandwater,ormoving
equipment.Aliveloadtypicallyactsverticallydownwardbutmay
acthorizontallyaswelltoreflectthedynamicnatureofamoving
load.
• Occupancyloadsresultfromtheweightofpeople,furniture,
storedmaterial,andothersimilaritemsinabuilding.Building
codesspecifyminimumuniformlydistributedunitloadsfor
varioususesandoccupancies.
• Snowloadsarecreatedbytheweightofsnowaccumulatingon
aroof.Snowloadsvarywithgeographiclocation,siteexposure,
windconditions,androofgeometry.
• Rainloadsresultfromtheaccumulationofwateronaroof
becauseofitsform,deflection,orthecloggingofitsdrainage
system.
• Impactloadsarekineticloadsofshortdurationduetomoving
vehicles,equipment,andmachinery.Buildingcodestreatthis
loadasastaticload,compensatingforitsdynamicnatureby
amplifyingthestaticload.
Dynamic Loads
Dynamicloadsareappliedsuddenlytoastructure,oftenwithrapid
changesinmagnitudeandpointofapplication.Underadynamic
load,astructuredevelopsinertialforcesinrelationtoitsmassand
itsmaximumdeformationdoesnotnecessarilycorrespondtothe
maximummagnitudeoftheappliedforce.Thetwomajortypesof
dynamicloadsarewindloadsandearthquakeloads.
• Waterpressureisthehydraulic
forcegroundwaterexertsona
foundationsystem.
• Thermalstressesarethe
compressiveortensilestresses
developedinamaterial
constrainedagainstthermal
expansionorcontraction.
• Deadloadsarestaticloadsacting
verticallydownwardonastructure,
comprisingtheself-weightofthe
structureandtheweightofbuilding
elements,fixtures,andequipment
permanentlyattachedtoit.
• Settlementloadsareimposed
onastructurebysubsidenceof
aportionofthesupportingsoil
andtheresultingdifferential
settlementofitsfoundation.
• Groundpressureisthehorizontal
forceasoilmassexertsona
verticalretainingstructure.

57. WIND LOADS 2.09
Windloadsaretheforcesexertedbythekineticenergyofa
movingmassofair,assumedtocomefromanyhorizontal
direction.
• Thestructure,components,andcladdingofabuilding
mustbedesignedtoresistwind-inducedsliding,uplift,or
overturning.
• Totalwindloadsaredeterminedbytakingtheproduct
ofthewindloadpersquarefootmultipliedbytheareaof
buildingorstructureprojectedonaverticalplanenormal
tothewinddirection.
• Windistobeassumedtocomefromanyhorizontal
directionandwindpressuresaretobeassumedtoact
normaltothesurfaceconsidered.
• Becausewindcancreatepositivepressureaswellas
suctionornegativepressureonabuilding,theforceisto
beresistedineitherdirectionnormaltothesurface.
• Designwindpressureisaminimumdesignvalueforthe
equivalentstaticpressureontheexteriorsurfacesofa
structureresultingfromacriticalwindvelocity,equalto
areferencewindpressuremeasuredataheightof33'
(10m),modifiedbyanumberofcoefficientstoaccount
fortheeffectsofexposurecondition,buildingheight,wind
gusts,andthegeometryandorientationofthestructure
totheimpingingairflow.
• Animportancefactormayincreasethedesignvaluesfor
windorseismicforcesonabuildingbecauseofitslarge
occupancy,itspotentiallyhazardouscontents,orits
essentialnatureinthewakeofahurricaneorearthquake.
• Flutterreferstotherapidoscillationsofaflexiblecable
ormembranestructurecausedbytheaerodynamic
effectsofwind.
• Tall,slenderbuildings,structureswithunusualorcomplex
shapes,andlightweight,flexiblestructuressubjectto
flutterrequirewindtunneltestingorcomputermodeling
toinvestigatehowtheyrespondtothedistributionof
windpressure.
Sliding
Overturning
Uplift

58. 2.10 EARTHQUAKE LOADS
Anearthquakeconsistsofaseriesoflongitudinalandtransverse
vibrationsinducedintheearth’scrustbytheabruptmovementof
platesalongfaultlines.Theshocksofanearthquakepropagatealong
theearth’ssurfaceintheformofwavesandattenuatelogarithmically
withdistancefromitssource.Whilethesegroundmotionsarethree-
dimensionalinnature,theirhorizontalcomponentsareconsidered
tobethemorecriticalinstructuraldesign;theverticalload-carrying
elementsofastructureusuallyhaveconsiderablereserveforresisting
additionalverticalloads.
• Theuppermassofastructuredevelopsaninertialforceasittends
toremainatrestwhilethebaseistranslatedbythegroundmotions
ofanearthquake.FromNewton’ssecondlaw,thisforceisequaltothe
productofmassandacceleration.
• Astaticallyequivalentlateralforce,baseshear,maybecomputed
forregularstructureslessthan240'(73m)inheight,irregular
structuresnotmorethanfivestorieshigh,andstructuresatlow
seismicrisk.
• Baseshearistheminimumdesignvalueforthetotallateralseismic
forceonastructureassumedtoactinanyhorizontaldirection.It
iscomputedbymultiplyingthetotaldeadloadofthestructurebya
numberofcoefficientstoreflectthecharacterandintensityofthe
groundmotionsintheseismiczone,thesoilprofiletypeunderlying
thefoundation,thetypeofoccupancy,thedistributionofthemass
andstiffnessofthestructure,andthenaturalperiod—thetime
requiredforonecompleteoscillation—ofthestructure.
• Baseshearisdistributedtoeachhorizontaldiaphragmabovethe
baseofregularstructuresinproportiontothefloorweightateach
levelanditsdistancefromthebase.
• Amorecomplexdynamicanalysisisrequiredforhigh-risestructures,
structureswithirregularshapesorframingsystems,orfor
structuresbuiltonsoftorplasticsoilssusceptibletofailureor
collapseunderseismicloading.
• Anylateralloadappliedatadistanceabovegradegenerates
anoverturningmomentatthebaseofastructure.Forequilibrium,
theoverturningmomentmustbecounterbalancedbyanexternal
restoringmomentandaninternalresistingmomentprovidedby
forcesdevelopedincolumnmembersandshearwalls.
• Arestoringmomentisprovidedbythedeadloadofastructure
actingaboutthesamepointofrotationastheoverturning
movement.Buildingcodesusuallyrequirethattherestoringmoment
beatleast50%greaterthantheoverturningmoment.
Thefollowingisabriefintroductiontothewayastructuralsystem
mustresolvealloftheforcesactingonabuildingandchannelthemto
theground.Formorecompleteinformationonthestructuraldesignand
analysisofbuildings,seeBibliography.
•Groundacceleration
• Thenaturalperiodofastructure
variesaccordingtoitsheightabove
thebaseanditsdimensionparallel
tothedirectionoftheappliedforces.
Relativelystiffstructuresoscillate
rapidlyandhaveshortperiodswhile
moreflexiblestructuresoscillate
moreslowlyandhavelongerperiods.

59. STRUCTURAL FORCES 2.11
Aforceisanyinfluencethatproducesachangeintheshape
ormovementofabody.Itisconsideredtobeavectorquantity
possessingbothmagnitudeanddirection,representedbyan
arrowwhoselengthisproportionaltothemagnitudeandwhose
orientationinspacerepresentsthedirection.Asingleforceacting
onarigidbodymayberegardedasactinganywherealongitsline
ofactionwithoutalteringtheexternaleffectoftheforce.Twoor
moreforcesmayberelatedinthefollowingways:
• Collinearforcesoccuralongastraightline,thevectorsumof
whichisthealgebraicsumofthemagnitudesoftheforces,
actingalongthesamelineofaction.
• Concurrentforceshavelinesofactionintersectingatacommon
point,thevectorsumofwhichisequivalenttoandproducesthe
sameeffectonarigidbodyastheapplicationofthevectorsof
theseveralforces.
• Theparallelogramlawstatesthatthevectorsumorresultant
oftwoconcurrentforcescanbedescribedbythediagonalof
aparallelogramhavingadjacentsidesthatrepresentthetwo
forcevectorsbeingadded.
• Inasimilarmanner,anysingleforcecanberesolvedinto
twoormoreconcurrentforceshavinganeteffectonarigid
bodyequivalenttothatoftheinitialforce.Forconvenience
instructuralanalysis,theseareusuallytherectangularor
Cartesiancomponentsoftheinitialforce.
• Thepolygonmethodisagraphictechniqueforfindingthe
vectorsumofacoplanarsystemofseveralconcurrentforces
bydrawingtoscaleeachforcevectorinsuccession,withthe
tailofeachattheheadoftheoneprecedingit,andcompleting
thepolygonwithavectorthatrepresentstheresultantforce,
extendingfromthetailofthefirsttotheheadofthelast
vector.
• Nonconcurrentforceshavelinesofactionthatdonotintersect
atacommonpoint,thevectorsumofwhichisasingleforce
thatwouldcausethesametranslationandrotationofabody
asthesetoforiginalforces.
• Amomentisthetendencyofaforcetoproducerotationofa
bodyaboutapointorline,equalinmagnitudetotheproduct
oftheforceandthemomentarmandactinginaclockwiseor
counterclockwisedirection.
• Acoupleisaforcesystemoftwoequal,parallelforcesacting
inoppositedirectionsandtendingtoproducerotationbutnot
translation.Themomentofacoupleisequalinmagnitudeto
theproductofoneoftheforcesandtheperpendiculardistance
betweenthetwoforces.
Vectorsum
d=momentarm
F
Moment(M)=Fxd
F1 F1
F2
F2
F3
F3
F4
F4